Turn your music up full blast anytime you listen to it. Try and schedule your music listening time conveniently when your roommate is sleeping or doing homework. Play music you know he or she hates. If they don't like music played, especially certain kinds, PLAY IT. If they don't like theT.V. on, keep it on all night, every night.
While your roommate is sleeping turn the T.V. or music up loud and turn the lights on. Start out by just turning the lights on for a few minutes. Then start to listen to your T.V. and music loud while the lights are on This will wake your roommate up and make them annoyed.