use irony. and make it funny- if you have seen nigahiga or David so? :) they sometimes use real life situations and give them a humour twist-really funny with their expressions and voices. try make abrupt funny scenes. people love that. but don't plan too much or else it ruins the video. hope i helped :D i also agree with spacespeck, gagey007 and brinnielynn :) and sometimes the quality of the video matters too! but don't worry too much about the quality at first
Have a shocked reaction to something, especially if its a macho guy screaming like a girl. Or look like you got hurt but try to not get hurt by using judo falling techniques, etc. Brain damage not worth a hit YouTube video, but it helps.