So admittedly I have never played a ranked game in my life. There, I said it. Now if you are still reading maybe you will benefit anyway. I don't claim that this is the best Shaco guide out there and I refuse to promise that your play style will fit mine but I have read A LOT of Shaco guides and have played Shaco too many times to count. Through trial and error I have arrived at this build and it works.

Decieve: This ability is a necessity for ganks. With its damage boost (Scales w/ Crit Damage) It delivers most of your burst. It can also be used to dodge abilities.

Jack-In-The-Box: This is great for escapes and traps. Although not much, the fear that it deliers can be the difference between life and death for you and your teammates. It is also the most important ability for your jungle clear. Ill go into this later.

Two-Shiv Poison: This is your "Oh no you don't!" ability. Use this mainly for finishing chases or poke enemy champs at low health.

Hallucinate: Spawns a clone. A controllable clone. There are two many combinations to name that you can pull of with this ult but to give some examples you can solo dragon at lvl 7 (difficult but doable, I suggest waiting until lvl 9) , diversions, baiting, doubling your damage, tanking turrets, etc. Also keep in mind that your clone gets all the items you build so things with on hit effects like Ravenous Hydra and Statikk Shiv do very well on Shaco

Because Shaco deals A LOT of damage by nature it would make sense to max out his ability to deal damage right? Wrong. Although this is a valid strategy I found that it was lacking. By using my rune page to up Shaco's Attack Speed and AD it left my masteries open to a little experiamentation. After a few days of modifications the masteries you see above were born. AS you can see I went 9/21/0. Now before you go "Ahxes, Shaco is an AD champ. You should up his damage." hear me out. Shaco already deals crazy amounts of damage without masteries to back it up. However Shaco also lacks defense and therefor the potential for a failed gank resulting in a feed is a bit higher for him than other champs. The solution? Give him defense. With the added health regen and defense not only does Shaco take less damage but he regens and therfor can sit in the jungle longer and if you play correctly you should only ever have to back to buy items.

Smite: Jungler Requirement.

Ghost: I take Ghost instead of Flash for one specific reason. I already have flash. With the Deceive ability Shaco already has a flash on a 15 sec CD instead of a 5 min CD. Instead Ghost will help you finish off the champs who use their own last minute flash to try and escape. Ghost also makes for great escapes.

Ignite: Good for finishing off those pesky champs that always seem to escape with 10 hp left. I prefer ghost but this is also a valid option.

Pros:
Crazy Damage
Crazy Escapes
Insane Backdoor Capabilities

Cons:
Squishy
Needs Early Gank to snowball or falls behind.

Always start in the lower part of your jungle regardless of what side your on. Top will usually be the one who needs an early gank so it will help when you are already at top lane when you have both buffs.
You want to begin to drop your Jack In The Box behind the larger buff monster at 58 seconds and continue to drop them until around 1:50. Duck into the brush. The buff will then attack the group of boxes while ignoring you. The boxes will deal enough damage that a single smite will finish the buff of for you while you pick up the tinier lizards. If done right it is possible to clear your first buff without taking any damage AND WITHOUT A LEASH. (Which means you don't have to worry about your teammate "accidently" taking your buff)
Next Take out wraiths. Drop a box in the center of them and begin attacking the large wraith first. After finishing off the wraiths que up two, YES TWO, health potions. These will keep you alive as you take your second buff without leash. Drop a box behind the buff and then back off. The buff should turn around to fight the box. Deceive in and attack its back for an extra 20% damage buff thanks to Shaco's Backstab passive.
After finishing your second buff you should be level three. Look at the lanes and determine whether or not any of them need a gank. If not go back into the jungle and begin farming your neutral camps for gold and xp so you dont fall behind. Keep an eye out though so that you can be there when your teammate needs your help for the kill.
How to gank: Hide in a bush close to your target. When target over extends Deceive in and get behind them. Drop a Jack In The Box behind them so they can't escape thanks to the fear that the jack in the box has. Throw Two-Shiv Poison and hit them for extra damage and slow. Continue to chase down and finish them off. If you did most of the work it was your kill. Don't be the guy to take someone's hard earned kill. It causes annoyance and then they don't want you to gank for them anymore. It is okay to bail out if you think its going to fail. Just be sure to ping that when you are going in or bailing out so that they don't get caught unawares.

SUPER IMPORTANT BECAUSE WITHOUT YOUR TEAMMATES YOU ARE SCREWED.
Seriously though. Shaco has insane backdooring potential an that could make or break a game. However in order for backdoors to be successful you have to communicate to your team that they need to
1.Distract the enemy team.
2. Keep them from backing out and going to base
3. Split push another lane and take some heat off of you
4. Have an escape route planned that will help you escape after the first three steps invitably fail.

WELL THAT'S IT FOR NOW GUYS. HOPE YOU ENJOYED MY FIRST BUILD GUIDE. GOOD LUCK AND HAPPY HUNTING. NOW YOU SEE ME, NOW YOU DONT.