first back should be a tiamat. if you can't build a tiamat straight way that means you arent ahead / didnt get a kill before you backed. which is perfectly fine. just build the components for the tiamat.

Do not forget control wards.

dont bother about the jungle item, shaco is the only champion that doesnt finish it,
Get a Triforce for your second full item if you are ahead. If not you can get a ghostblade to keep up with damage if you're really far behind.

Ganking as shaco will never be easier.
I don't gank until level 4 or 5. just because at level 1 your Q only last for about 1.5 seconds , which is literally nothing. Once you get 3 points into Q, your Q last the same amount of time as the old shaco did which is 3.5 seconds. With that amount of time you can gank from the lane and they wont even know you were down there.

Of course you should always be trying to counter gank so make sure to always stock up with control wards so you know where the enemy jungler is

In team fights you should be the one hidden somewhere, waiting to go in on the squishies, if you're going the burst assassin build, however if u decide to go the bruiser build you still play the same just you have to rely on you're team to follow up because you could get kitted pretty easy and not manage to kill someone

Pros
1.Good clear with tiamat
2.Good ganks
3.Stomps early game if ahead/and late game
4.Outplay potential
5.Can solo dragon and rift herald very easily while your clone tanks the damage

Cons
1.Hard to come back if behind.
2.Relies on follow up sometimes.
3.Gets kitted easily
4.No escape when you go in