I will show you how I play one of the funniest champions of League of Legends, Shaco. This is a build for aggressive players so those who like to play defensive, you could have to change some items ot masteries.

Playing Shaco have advantages and disadvantages.

Advantages:
-Deceive helps to get away
-Slow
-Fear

Disadvantages:
-Squishy
-Low survivability

I'm using critical strike runes to get the bonus early game so it helps farming minions or neutral monsters. You could use Armor Pernetration runes too.

Boots of Swiftness:I want a high movement speed that will always work, even if i am in a fight. You could use Boots of Mobility but i think that we could need the speed of Boots of swiftness in a team fight.

Trinity Force: I take Trinity Force for the bonus attack damage given after casting a spell so i can do much more damage after casting Deceive.

Warmog's Armor: I think that Shaco is a very squishy champion so i take a health item to increase the survivability in team fights.

Phantom Dancer: I take PD for the attack speed and critical strike chance bonus. It also give some movement speed that could help me getting away or chasing an enemy.

Infinity Edge: I take IE to get the damage and the critical strike damage.

Bloodthirster: Im ending with Bloodthirster because lifesteal is not essential but could be useful. It also gives a fair amount of damage.

Optionnal Items

You could want to change items so there are some that could be useful:

Madred's Bloodrazors
Gardian Angel
Youmuu's Ghostblade
Banshee's Veil

Im farming lot of minions when the game just started. When the opponent come to you, try to throw Two-shiv poison, use deceive on that opponent and hit it. After put a Jack in the box in front of him so he will be fear. Do the maximum of damage in that time. If you see that you can kill it use exhaust and finish it, if not just go back to your minions and wait for another attack. When you get your boots, you should try to gank on different lanes. Prepare your ganks with your teammates and try to help them to have a kill.

Now some team fights could start to explode. At the right moment, jump with deceive in the ennemy team and put you box. After, try to focus an opponent with you double that you created with Hallucinate.

Late game, you should take your double. He can tank the ennemy turrets for you so try to backdoor your ennemies and destroys their last buildings and get access to the ennemy nexus.

I hope you liked that guide. Maybe you won't do good games with it, you are just not aggressive enough for it, just change your items, runes and masteries so you should get it.