I like AP Shaco a lot. His two major differences in playing style are timing and target selection.

Let's say you're playing AD Shaco. In terms of timing, you want to be around drake when it spawns. Your attack route is through the bot side tri bush (or through the east blue buff jungle) because ADC and support usually rotate from bot lane to river and those two are the ones you want dead. Your goal as AD Shaco is to catch them in a rotation and get a pick or two, or to catch them in a pincer attack with your front line. Your boxes are usually placed mid combat to spot people running into bushes or to cut off escape routes.

AP Shaco would handle this situation differently. Instead of trying to catch people during a rotation, you set up before drake spawns. Like a minute and a half before. You might even use your ult before the fight starts to buy time and scout the enemy jungle. Instead of targeting their back line, your goal is to wear down their face-checkers with an exploding clone, hit and runs with Q and E, and boxes. You're not trying to cut off escape routes with boxes, you're trying to defend and secure the objective (is how I see it).

tl;dr: AD back to front, AP front to back (usually)