Without getting in to great detail, I run a rune page for casters (including Teemo as I play him that way) that gives me ~10% Cooldown reduction and ~5 HP/p5. For Masteries, I use a fairly common 9/0/21 -- yielding another 9% CD reduction. The CD reduction is a large part of why I build Teemo the way I do, however, I don't feel it's required to play him successfully with the below item builds.


Summoner Spells: Without exception, I always take:

• Teleport - Teemo's mobility is incredibly important, and given that you can Teleport to Mushroom locations, it's an invaluable skill.
• Flash - Given that Teemo is the fastest (or one of the fastest) Champions, people love to focus him with slows and stuns -- especially early game, when he's really squishy. I find Flash amazing for escapes early and mid game. Late game, Flash is amazing combined with your speed for running down Champions and getting behind teams to drop Mushrooms in their path just before a team gank.

Skills:

Note: As I always try to solo mid on Teemo, even if against two Champions, I play him for mid and late game, focusing on harassing and surviving early game. Basically, I like to get stacked before I really start hunting (around level 12 -- Move Quick [2]).

Level 1: Move Quick (1) *
Level 2: Blinding Dart (1)
Level 3: Toxic Shot (1) *
Level 4: Blinding Dart (2)
Level 5: Toxic Shot (2)
Level 6: Bantam Trap (1)
Level 7: Blinding Dart (3)
Level 8: Toxic Shot (3)
Level 9: Blinding Dart (4)
Level 10: Toxic Shot (4)
Level 11: Bantam Trap (2)
Level 12: Move Quick (2)
Level 13: Blinding Dart (5)
Level 14: Toxic Shot (5)
Level 15: Move Quick (3)
Level 16: Bantam Trap (3)
Level 17: Move Quick (4)
Level 18: Move Quick (5)

* If I'm against a team whose Champions aren't very harass, I'll get "Toxic Shot (1)" at Level 1 and "Move Quick (1)" at Level 3. That's up to you, I find having Move Quick early is really good for running away and running in for a quick Blind/single tap to apply Toxic Shot. It's also good for running off to the sides to drop your Mushrooms and get back in the lane for continuous XP gain. 


Items:

I always use to get annoyed at Guilds for not giving an exact build, but after playing a Champion like Teemo, I can see how all builds are subjective to the team your against. However, I do feel that how I build Teemo is a large part of my success with him, so I'll give you my primary build, followed buy how I change things for certain situations.

Primary Build: (in order)

Note: I'm going to assume frequent trips back to the shop, however, I rarely have to go back before level 12 with 3K+ gold. But it's really dependent on who you're against.

• Meki Pendant -- starting item
• Health Potion x 2 -- starting item
• Boots of Speed
• [final] Fiendish Codex
• [final] Sorcerer's Shoes
• Sheen
• Stinger
• Catalyst the Protector
• [final] Rod of Ages
• [final] Lich Bane
• [final] Nashor's Tooth
• [option 1: final] Frozen Mallet
  • If survivability and/or chasing is an issue.
• [option 2: final] Zhonya's Ring
  • If having no issues with survivability and just want more dmg.

Now, as I said, that's my Primary (or standard) build, however, I do tend to vary that depending on who I'm against. Here are a few things to consider:

Spell Block Build:

I mainly use this against a very well played Ryze, Fliddle or Veigar (especially if there's a combination of two or more of them).

• Meki Pendant -- starting item
• Health Potion x 2 -- starting item
• Boots of Speed
• [final] Fiendish Codex
• [final] Mercury's Treads
• Catalyst the Protector
• [final] Rod of Ages
• Negatron Cloak
• [final] Abyssal Scepter
• Sheen
• [final] Lich Bane
• [final] Frozen Mallet

Note: With either build, if I'm getting really harassed early game, I'll build a "Philosopher's Stone" over "Fiendish Codex". However, if I do that, I usually try to get the Codex Later for the CD reduction.

A few other items to consider:

• Mejai's Soulstealer -- If you have CD reduction from both Masteries and Runes (as I do), this is a very good item for maximizing AP. If I take this, I usually build it as early as possible (skipping the "Fiendish Codex") so as to get as many AP increases as possible from kills.
• Guinsoo's Rageblade -- I haven't tried this yet, but the theory crafting makes it seem like it would be really good for a little boost to damage (mainly for tower pushing IMO), especially in combination with Nashor's Tooth. From what I hear, there's benefits to stacking two of these. Don't quote me on this, but something to do with it taking less hits to get a max AP boost from the passive.
• Boots of Mobility -- The extra movement OOC would be awesome for getting behind groups to drop Mushrooms and placing Mushrooms near deep lane towers for later ports.

Mushroom Placement:

One thing to keep in mind when placing, especially in smaller paths leading in to lanes, is that most people don't run right in the middle of the path, they tend to cut corners. Mushrooms have a fairly small hit box, and chances are people will miss a placement in the center of a path if they cut the corner tight. For that reason, I always drop my Mushrooms on edge of the path that I would take, running away (I play very defensively).

I'm not gonna get in to specifics here, that would take pages. However, here's a few general rules broken out in to five sections;

1. Coverage - basic map coverage, the purpose being to catch unsuspecting runners and attackers and aid your team by allowing them to incorporate your Mushrooms in ganking strategies.
2. Defensive - strategies for thwarting harassing and ganking.
3. Offensive - strategies for aiding your and your team's ganks.
4. Action - strategies for dropping Mushrooms in mid combat to either aid in killing or escaping for you and your team.
5. Mobility - placements for Teleport mobility.

Note: Of course, some placements are going to over lap, for example, "Coverage" placements can and should be used in the other four situations.

Coverage

In general, I consider "Coverage" placement to include; 

• Grassy areas in the rivers, especially right in on the edge of the middle lane, on both sides.
• If starting in mid, I like to drop a few on both sides of the middle lane, out of the direct pathing of creeps, but close enough to that path where you can lead creeps in to it, if trying to take out a wave without your own wave. This is really good for slowing a hard push early-mid-game.
• Neutral Creeps: I like to place a Mushroom in front of all buff giving neutral creeps, while not likely to yield a kill -- it's very annoying. Also, in the grass in front of Dragon and Baron, which helps with "Mobility" too.
• Smaller lanes feeding in to larger larger lanes, especially in mid, as people use those lanes to travel from lane to lane.
• In front of towers, to take out pushing creep waves and annoy/harass pushing melee Champions.

Defensive

This is especially important early-mid-game (levels 6 to 12).

• Against stealthers (Eve/Twitch): I typically litter the ground to my left and right, slightly behind me. This serves two purposes. First, it means that if/when they do go in for the harass/gank, you can easily lead them through your Mushrooms when running back to the tower. Second, chances are, they're going to pop one while trying to get in position alerting you of the presence and often making them reconsider leaving stealth.
• Against slows and stuns (e.g. Judicator/Ashe/Scion/etc): As above, sides are good, but I also try and place one directly in front and behind me while creeping. Obviously, you're going to continue to move forward or backward while the lane is pushed one way or another, but either way, this is good. Either you're turning you lane in to a Pac Man board while pushing forward, or you slowing creep pushes with the extra damage.
• Later game is better covered under "Action" and "Offensive", but it's important to note that when jumping in to a lane to quickly push a tower, I ALWAYS drop a Mushroom where I think a gank will most likely come from. Typically at the closest small path leading in to the main lane. If the gank comes from somewhere else, you can always use that path as an escape route.

Offensive

• When setting up a gank, solo or with my team, I like to take a little time and get a few Mushrooms down first. It's not always possible, as game situations change quickly, but basically, I plan my escape route on my way to the gank and drop at least one Mushroom on the way there. I then try and get behind the target and drop another Mushroom directly between them and their closest tower. This takes some timing, as you don't want a creep wave to eat it before your target does. If time permits, another Mushroom in what might be their alternate escape route is good too (see the last bullet point in "Defensive").
• While pushing and/or fighting with my team, I drop a mushroom on every cool-down, either where I'm standing or slightly off to the sides -- really this could be consider more "Defensive" or "Action". However, I call it offensive because so many of my kills occur after my team is broken and retreating and the mid-hp enemy pops a Mushroom while chasing (I always watch for this) and I turn around and finish him off and Flash out quickly before the rest of his team stomps on me. It's a beautiful thing!

Action

This probably doesn't need to be it's own section all sections include things that should/could also be in here, but here's a few words on it.

• When/if you get caught by multiple enemies and have no escape, drop a Mushroom. Chances are they'll pop it and even dead it's damage to their team and slows their movement. A single Mushroom at level 18 with good AP can do over 1000 dmg, if 3 people are hit, that's 3K+ -- not bad, especially if your team is moving in for a counter-gank. I've gotten triple kills by doing this just before dying when ganked at my tower.
• In a large team battle, run in to the middle of things and drop a Mushroom and run out again.
• When chasing, pop your Move Quick, avoiding creeps (don't want it to break) and, catch up to them and Flash past them and drop a Mushroom. Done and done!

Mobility

This is really important, especially if your team has strong tower pushers with Teleport (Sivir/Ryze/Taric/etc).

• This is really basic and simple: Take a minute or two, after you have your final boots and at least two levels of Move Quick and run though the woods to each enemy tower and drop a Mushroom in the grass near by. This give you and your team mates a stealthy place to Teleport in to for a quick tower kill. It wins games hands down. An added bonus is, if you choose this placement well, it also covers all four of the other placement sections.

Countering Vision Wards and Oracle's Elixir

A quick note on this, because both of these are really annoying! For the most part you just have to play like you don't have Mushrooms for a little while -- three minutes in the case of Vision Wards. For Oracle's Elixir, mention who has it in all-chat and ask your team to focus on killing that person first or help you put together a gank on them. Another thing I do in either of these cases is focus my placements in the grass. In most cases, neither of these consumables will show your Mushrooms until the enemy is actually in the grass, so if you really litter the grass in the river near mid, you can usually bait them in to one or two of them before they notice their there and hopefully get the kill off it.

Attack Tactics:

Basically the title of this post: Stick and move. With an AP build, you're relying on Blinding Dart and Toxic Shot, along with your Mushroom placement for Champions kills. I consider this build more support and play it as such, but still manage a large amount of kills, while only a few death. Ideally you will rack up a ton of assist too.

The goal in on this is to bait them to you and in to your Mushroom(s) as well as your team. However, just simply off your tower or teammate long enough for reinforcements is fantastic.

Here's a few points on Attacking and retreating:

1. At all levels when solo against another Champion, I run in Blinding Dart, auto-attack and then retreat towards my nearest Mushroom (level 6+). This is usually easy to do without getting hit, however I don't turn on Quick Move until I'm retreating and out of range (or between their cool-downs), in case I do get hit, don't want it to be on CD with a faster Champ chasing or slow on me.
2. If they don't follow, or don't catch me, I wait for Blinding Dart to be up again and repeat number 1, coming from a different direction if possible.
3. If they start backing off, I'll push them until they are dead, at a tower or totally retreated.

Note: I've seen AP Teemo played aggressively well, however, it's just not my style on him.

Well, that about sums it up. I started this intending for it to be a "Mini Guide" but it seems to have expanded in to quite a bit more than that. I left it called "Mini" because I don't cover his spells/abilities or history. Thank you for reading and constructive criticism is encouraged -- on that, I'll say, the other Teemo Guides out there are very good, and very valid ways of building and playing him, this is just another way.

Thanks!