Shaya, teach me to play lane Shaco plz
Okay. I am lane shaco.
I get jack in the boxes level 1, because I am the
boss.
Is it possible for my team's jungle to be invaded?
No. Try it (unless my team just has absolutely no way of capitalising on 2-4 half second aoe stuns that come one after the other).
Do I increase the speed of my junglers through a jitb at a camp or two? Yes.
You play with a bottom lane that can [help] control the flow of things / high sustainability. Your lane is nearly ungankable, and you can counter aggressive play from your lane enemies with smart play as well.
Sivir and Caitlyn are very strong ranged carry partners for Shaco.
Soraka is amazing for UNRIMITED SHIVS and gives shaco the ability to last hit a bit. Supports are good in general because with the utility/support of GTFO jitbs they can be reasonably safe while shaco... goes elsewhere.
Rumble/Jarvan/Noct and the likes are extremely strong as well. You want lane partners who have ranged aoe of some sort, because Shaco can last hit creeps in melee range and capitalise on confrontation. Of course partner with a stun or snare is likely results in someone being chain cc'd for like 3 seconds and then you can deceive to chase them after flash.
You jitb both brushes, you force the enemy to not be able to zone you from the brush.
You work with your jungler to gank, invade, zone dragon/baron. You still have great pushing presence without needing to be with the team at dragon/baron because someone else on the team has smite. That is, if you're going AD Shaco.
If you're AP Shaco you just zone all choke points to a tower and just shiv people who are stuck until you dive them. Using your clone to take tower aggro so others can move in without the initial tower damage.
Shaco has too many responsibilities as a jungler so it's often very hard to do all the many many amazing things he can do while still handling the jungle portfolio.