Pathing Picture...

With Twitch JG your early game is everything. Sure you can come back from a bad start but getting the snowball early on is what makes this champion so good in the jg. You always want to start at your red even if your top or bot lane refuses to leash you should be able to take it out fine. Right after taking your red you want to head to your mid lane for an early first blood about 90% of the time.
With your first gank make sure you are able to do your best to get behind the enemy mid laner with your Q. After that begin attacking him moving back as he dose if you dont take ignite and opt for flash then you may have to flash to get full stacks. DO NOT TRY AND E WITHOUT FULL STACKS! They might seems supper low but trust me that last stack matters. There are some mid laners however that you will be unable to kill such as Fizz or anivia. With these try to lower there health and apply presure before going to get your scuddle. After scuddle you want to head bot get your gank off and then begin clearing your jg in the order listed in the Diagram above.

Twitch being the squishy champion he is is very easily invaded. Having good vision is key with this champ more then any other jgler. His invades are not great however you might be able to againsed tanky champs such trundle or other tanks do to your ability to kite them rather easily.

With twitch jg farming is one of the biggest issues. Allot of players get ahead with a few good ganks and then keep ganking continuously negating there farm. This works for a while but if the enemy jgler is smart and farms rather then applies allot of counter ganking he will soon pass twitch in items and dmg. Enemy champions are good sources of gold early one but if you kill them and there gold value resets soon you will be making no profit from you ranks.

Twitches kit is all about bursting champions with your autos and keeping your distance. Your Q Ambush is his strongest ability and what makes this champion so fun. Unlike Eve with her passive at lvl 6 twitch can become invisible lvl 1 if he wants making his early ganks amazing. His W Venom cask is a good slow for kiting and should not just be used for dmg unless you are sure you can get away after. His E Contaminate is a stacking ability allowing for high burst dmg if you can get the stacks off as well as decent range if a champion flashes or dashes away from you at low health always keep it as a reserve unless they are trying there hardest to kill you. His ult Spray and pray are what realy makes twitch annoying. The ability to auto attack from such a far distance and do so much dmg makes him very hard to kill if played correctly.