I need to lose 12 pounds 
Google this but in a nutshell, drink 2 gallons of water daily until maybe 2 days before weigh in.. Start cutting down and day before weigh in, stop drinking and eating entirely... 4 hours before weigh in, hit sauna and use albolene generously on your body.. Might wanna hit the bike for 5 minutes beforehand to get a good sweat going right away.. And get a sauna suit also ($10 at sports authority or dicks)