Look at your question... For the sake of any deity you may or may not believe in! If you can't win on the merit of your own work then dont ask genuine designers for underhanded methods of boosting your chances. Get a grip. If you're determined to waste your time on such things, if you want more votes, enter better work. BECOME better. Improve your skills. Be the best you can be, then get even better. Then realise such competitions are pointless at best and a rip-off at worst and don't enter them, and produce your own personal projects instead.