This is my first guide, and no, I do not play ranked. This build is the build I use, with a few modifications depending on enemy team. Teemo is a great character to play, both fun and powerful is played well!

I choose to maximize my attack speed for my on-hit effects to wreak havoc on the enemy team mainly during team fights, but also to be a great 1-v-1 fighter. The mana regen is simply that, to help regen mana. Yes, all of this so far is very simple, but effective.

The masteries I have chosen maximizes your Teemo killing potential, while also allowing you a great move speed bonus that greatly helps with ganking between lanes and positioning for team fights.

Pros:
Fast
Powerful
Great anti-tank
Hard to defend against
Fun to play!!!

Cons:
Easily killed
Normally focused
Tends to be hated, a lot.