Often when laning, you want to be on the edge of your attack range (you may make a keybind to show attack range), as many botlaners (both supports and ADCs) tend to have a more agressive style. Twitch, on the other hand, generally doesn't care about his KDA as longs as he has certain items on a certain minute of the game. That's why this champion is so versatile and is played by me on every role in the game.

Speaking of that...

Your enemies likely haven't seen Twitch at all, and most certainly haven't seen Twitch Toplane, so you should play off of their confusion with a new matchup. It's also best to go for a lvl1 trade on Toplane and Midlane as an AP Twitch, surprising the opponent with your E damage.
Most of the time, the key to laning against a melee champion is to watch his attack range. If you're lucky, you may also secure priority on your lane. In that case, don't drop it for nothing, but also don't overstay your welcome.
Your Q is your main anti-ganking tool. Your Q is also your main engage and disengage. I find it best to walk to an opponent within Q's stealh range and engage, they would likely have walked away too far by the time they realize that Twitch's here, so they'll be forced to "Fight of Flight".
As a Mid\Toplaner, don't be afraid to roam if you did really well or really bad in your lane.
Your first back should be for the boots no matter the role.

When you have gained enough items and confidence (or even broke the enemy's tower, bonus points for that), your game becomes that of roaming. You should look for short, advantageous fights, your Q reset enables you to seamlessly walk out of them afterwards. If laning was harsh for you, you may use your mobility in order to splitpush. Of course, you shouldn't be buying Hullbreaker and AFK killing minions. You should use the push you create in order to pressure the enemy team to rotate and enable your teammates to do something useful around the map.

Now for the teamfighting itself.

You obviously belong in the backlane, and I'd recommend to not start a fight without your Q and\or R. Your R may be the gamechanger in most of the 5v5s (especially with on-hit you get later). I'd highly recommend you learn how to kite (or even glide)beforehand, as it's a skill Twitch takes advantage of on every position.

I'll keep it brief, as there's not a lot to tell about jungling. You may suffer from lack of damage to camps in the early game, but your pet should be able to carry you. Once you've done around 2 full-clears, you, like a Mid\Toplaner Twitch, should be looking for easy roams, but this time keep the objective timer in mind and plan your path with every back.