I have cut down my WBTBs to about five minutes.
Drink lots of water or apple juice before bed, and you'll probably wake up after your 2nd/3rd REM period. Go to the bathroom, drink more water/apple juice, jot down a few notes on any dreams, and go back to bed to WILD. It helps if you have dim lighting, because light affects the melatonin in your body, and can keep you from sleeping. I don't use alarms because they startle me awake.