These are my both teemo builds. I play him very often on ap, ad, and as tanky teemo these are my best guides for him. Enjoy and rate pls. You can give me other opinions too.
stroh999

At both teemos I got two boots. There u can do your choice too. And realize your opponent team. If their are many ap or cc go for the magic res boots. At tanky teemo are armor res boots. Thats yours if their are prob. no cc or 3 or more dps. It`s passive give u 12% dogde. Good against DDs.

Sometimes I have 2 times 9 diffrent runes of one colour. Their u can chose between both. It´s your choice.

flash and exhaust are at this time the best choices for teemo. Couse you can both use to escape and chase.

at rankes if u play good u can win games. U will get him oftenly couse there are often no bans and picks for him.

It´s no good idea to jungel with him, couse u had no real assasin spells. But on solo or mid u can do great last hitting with your [E]. If u can get a red buff grab him. U can do some great last hitting with red in combination with [E]. U shot on the creeps inthat order the big one/caster/caster/caster/1caster/2caster/3caster then last hit all creeps in a weave.

pros: good solo laner, can also go mid.
if u play him well he do a tons of dmg.
good at teamfights and at one on one.

cons: he is no real tank.
he is no real dd.
he is no real caster.

but in summary there are better pros as cons.

He work well in team fights couse u can slow and crash the enemy carry full out of that teamfight. (darts only on dps)
1. get behind your team.
2. don´t engage
3. and shot your q in this order :
1.dps/carry
2.dps/meele
3.tanks
4.supporter
5.mages

At least i hope u enjoy my guide, rate it and put a comment (pros/cons acceptet) below.