I've never actually used the site myself, but I have watched others do funny things in videos on youtube, and I would suggest something musical. Here's an example.
haha ANYTHING. dress up as a cat, that always gets some interesting comments. although i prefer omegle to chatroulette, less creepy old men jacking off
My friend & i used to go on there with crazy makeup or masks. I wore a dalmation mask & she painted her face like a clown. :'D
I LOVE this guy XDD I saw him on YT a few months ago :P my favorite is always 33333333 33333333 mother fu***** 3 XDD
make an improv (like play guitar) and upload it on youtube :)