Try to engage team fights as killing adc/apc (or both ^^)
Your role in team fight is kill adc,kill apc, and die or escape.
Then if you escaped and you don't have low hp, wait for Q cd and then go to help your team as
killing another enemy champion.

Hybrid shaco combo is AA+E+Hextech active
(Crit from Q+e+hextech will kill every paper champion :D)
Try to use your passive every time you can.

Start with machet and three potions (you don't need flask).After first recall buy bue smite enchant and boots(and x2 long sworld if possible).Core items are 1)Blue smite enchant-warrior,2)hextech gunblade,3)duskblade or darkttharr and 4)magic penetration boots.

Acceptable items are:
-Rabadon's deathcap *if enemys haven't much magic resist and you need more ap*
-Void staff *if enemys have too much magic resists (it's good anyway becouse of it's incraseing our damage)*
-Luden's echo*if you need a little more damage, and enemys don't have too much magic resists*
-Lord's Domnik's regards *if you need more ad, and enemys have hard tank(if you're going to buy this, buy void staff too, it's scaling so good)
-Mercurial scimitar *if you need ad and enemys have hard cc*
-Zhonya *if you need damage and some survi (or you want to bait enemys like ***** ^^)*
-Liandry *if you need ap and some hp, and enemys have magic resists*

SHACO WORKS GOOD WITH (*near names of champions that are the best with shaco)
-*RIVEN
-*MORGANA
-ORIANNA
-VAYNE
-*THRESH
-*LULU
-KAYLE
-*SORAKA
-JINX
And every champion who can let shaco survive in team fight (=

If you won't go counter jungling put in 0:41 two boxs at bit golem,and two boxs near red.
Botlane have to help you with golems(smite it).Then add skill point in E and use it to agro red on you and put one box behhind it.Then clear all jungle.

If you want go counter jungling:
0:41 all boxes on red.Then after you kill it add point in Q and go on enemy blue, take it and run away(if enemy was doing it try to kill him ofc).And remember to care about enemy lanes.

Ganks with shaco are not hard, use your Q to get on the lane, then put box on enemy's escape way,remember that your aas are slowing so use E at the end, if enemy have big sustain or heal summoner spell ignite him on start.Gank everytime you can, even if you are counterjungling