First of all, I need to inform all of you that this is an off-meta pick, so you dont hope it to work the first or second time you try it but when you get used to it you could have a lot and I mean A LOT of FUN.

So you made it here, at least, lets take a look to what we have to do with this rat.

Early game is a bit hard if you and your support dont understand each other, this can be solved easily by duo with a support you trust and you two can communicate well.

Twitch in the early game is the 'reseting' champion so hes good for early fight with his Q reset every kill or assist, so try to find any opportunity to join an invade or help your jungler in first dragon.

The landing phase could be harsh but nothing to worry about, Hail of blade Twitch can do quick trade or even get kills early and do the snowball stuff.

But not all good thing comes to you, and heres some tips to stay in the game.
And, this sound really really stupid to high elo so please ignore this, this is for low-elo players.

1. You dont have to get all the minions.
Sure, farming is essentials with adc, but if that mean you got poke to low and cant join fight, its not worth it. If you're on the strong side, keep your health so your jungle can have more confident to gank your lane or have you ready to fight back if their jungle invade.

2. Roaming.
When the situation get worse, you cant farm neither get kills, roaming is your only option left. When a Twitch is behind, the enemy will try their best to exploit you because you're just a harmless rat with less health than even a jungle camp, so stay with your laner, if you cant win your lane, help other lane so you can keep your present in the game.

3. Advoiding combat.
This may sound ridiculous but you should know what fight you can join and what you cant, again this is for low-elo, keep your cool head, warn your teammates and try to farm so their 5-0 Samira wont get triple kills or even quarda in the dragon fight.

You made it to the mid game, you're a big threat now if you're ahead the enemy, but if you're behind, you still a threat, just dont throw.

In this time, some canon event may happen to you, or your teammates so you can blame them when you lose.

1. You got caught with your sup.
This is stupid, really really stupid, why are you in this situation? Where are your team? To advoid this please go with a tank and advoid any bush you think have an Assassin inside.

2. You caught their carry but you're now low on health.
This build all serve for one purpose and it all said in the title, One-shooting their carry.

So you see their caitlyn or Aphelios went alone in bot lane for some reason, maybe they're stupid like your teammates and you caught them right before a big fight, this is a win win situation right?

Sure, it can if you have a healing support and you still have your R up, bcs there is just not much you can do in a big fight without your R and their carry is dead so you're kinda out of duty now, but you can still help get objective, like towers, this build can shreed tower faster than you think.

3. You completely useless in team fight and even in catching enemy carry.
This is bad, you know you're not gonna chat all "ff" every minutes or your sup can do that for you since you're such a failure, plus saying "Adc gap" and you can do nothing about it since it's all your fault.

Idk, you made it here, what did you expect an Assassin to do in the late game?