Hi, im piniczekowr, EUNE player that has over 800 ARAMs played. Currently on ~1600 MMR in ARAM mode, according to summoning.net site. After recent patch introducing Luden's Echo I realized how broken AP Shaco is, so I decided to share this knowledge with you :)

Pros:
+ Can 1 hit squishies
+ Hard to catch
+ Can pull off crazy plays
+ Troll all day, fun to play
+ ***issin Teemo, for double annoyance

Cons:
- Squishy himself
- Shut down by CC, burst and Oracles
- If you mess anything up you're dead

General tactic is to take the new "Mark/Dash" summoner spell and Ignite or Flash (if you're feeling unsafe).

You have to hit an opponent (anyone tbh), dash to him, throw E (Two-Shiv Poison) on the nearest squishy, then Q away (optionally drop a box too). Super efficient and super annoying method of poking, often gives you free kills on an unexpecting opponent. Because you will max E first, damage after getting Luden's Echo at lvl 9 is ridiculous. However, your damage will rise only up to ~1000-1300 at full build from E, which is not enough to 1-shot enemy ADC. Adding Lich Bane AA to the combo will increase damage enough to nearly guarantee a kill together with Ignite. Downside is that staying for one more AA in the middle of enemy team lategame may cost you your life. And makes your combo much harder to pull off, since you have to hit your target with snowball directly.

In teamfights with alot of AOE, your job is to eliminate enemy ADC. After you do so you may as well die, because you're pretty useless. But before you do, press R and try to lure enemies into killing your clone, with this build its large AOE damage, similar to Annie's Tibbers, but without stun (free kills).
Its important to place traps before teamfight starts, because if you place them in the middle of AOE damage they dissapear instantly. They trigger on minions too, so watch out. Also useful for taking down turrets, just place them on the turret and they will attack it, for some nice damage. You can use your R in the same purpose.

In general troll as much as you possibly can, and make opponents so furious, that they will chase you, instead of your carries :) Just as Teemo does.

This build/method of playing (relying on E instead of W) can easily bring you victories, most damage done and "gj" saying teamchat.

Last few ARAM games with AP Shaco: 26/18/26, 13/9/20, 10/9/19, 17/7/29, all won.
Have fun summoners :)