So this is me, just wanne explain how i play Teemo and how i find him really fun!
sorry for the possible bad english and feel free to comment my mistakes.
If you have any input in the build where you think i'm doing wrong or it could be better comment and i'll try to explain my reason for it...

my rune build is just an overal decent rune build and it's my only my first full page i got so post better ideas...

normal dmg mastries wich i think is best for this build, bcause i really focus on dmg and trust my team to protect me when needed or just run into my shrooms and leave my enemies behind me with epic movement speed.
The utility mastries are always handy for the little extra mana and hp regen, the extra gold and of course the extra xp wich will help a great deal in lvling and shrooming.

my item build is mostly att speed based, the main dmg of this build comes ofcourse from maldred's and in the end (if you get that far) the bloodthirster. The nashor's tooth is great for Teemo for 3 reasons:
1. it adds huge attack speed
2. the ability power adds nice dmg to your poison and ofcourse to shroom power
3. the cooldown reduction is very nice for planting extra shrooms and for move fast when you've been hit, an extra fast blind is always welcome ofcourse.
the frozen mallet adds that hp for survivability but thats not the main reason i get it. The slow is the main reason, it adds just aswell survivability and attack capability, the slow makes doing hit and run way easier and also makes chasing fleeing enemies way easier.
The bloodthirster is more for some extra physical dmg and the lifesteal is always welcome. ( if any1 has a better idea comment)
If you feel like getting focusd you can always put in a banshee's veil where you feel like it fits best.

exhaust: for slowing fleeing or chasing champions but more often i use it to blind those stupid melee champions who think they can solo you in like 1 second. Put your blind skills first then exhaust and then blind again.
clairvoyance: i use it to see incomming ganks or catch lane switching enemies by suprise. Always handy to check buffs for squishy junglers who you can then go gank.

blink: good possibility if you have trouble escaping with your shrooms and moves peed.
burn: always handy for those mundo's out there or just that little extra dmg.

pros:
- nice dmg
- high att speed
- lot of shrooms on the map
- quite high survivability
- good movement speed

cons:
- squishy
- pretty useless when focusd

when you don't play smart you will get killed!

you are a great farmer but focus on last hitting minions
try to minimize auto attacks so you can reat fast
try to keep moving to confuse your enemies and dodge free shot skills
when a melee champion tries to attack you, just blind and walk away. most of the time this will make him go b and when he chases you, run into shrooms and finish or run to the closest turret

jungling: leave the normal neutral monster for some1 who cant farm that good,
all buffs are good tho so when they are up it's always good to get those.
Aspecially golem buff for more shroom planting

only one rule: DO NOT ENGAGE
when you engage or stand open for your enemies to get you you will die, bcause you are squishy

always remember you have camouflage so try to use it as much as you can.
when you try to gank an enemie stand in bush and camouflage this way when they expect a gank and check the bushes you won't be there.