Training for a bodybuilding contest really isn't too much different from your everyday training unitl you get into the final weeks of your preparation.
During these final weeks, you really begin to concentrate on your weak points that will show now that you have become leaner.
As your show nears, you must take appropriate measures to be sure your muscles remain "full" and thick. Most individuals think that means reducing the weight and increasing the reps. This is only true for some individuals. But not everyone!
I suggest you keep the weights heavy so you don't lose muscle, but to burn more fat reduce your rest between sets, do circuit training, super sets, tri sets, giant sets, etc.
Eating plenty of carbs and not reducing your calories too much will also help keep you full. Reducing your carbs too much or improperly can give you a "flat" appearance and wash out any vascularity/hardness you may have had.