Meditation and visualization. I picture how I want to look. My entire motivation behind my willpower is a single photograph of me. I keep a printout of it with me at all times. I also keep a bag of cajun beef jerky and a bottle of water with me at all times. Every time I crave something and can't get the thought out of my head, I look at the photo, have a chunk of beef jerkey and nurse the water for an hour. The jerky is zero fat and has almost no calories. The water keeps me full and helps flush my system.
Now, you may look at a photo like that and get depressed. For me, that photo is my ultimate motivation.
That is my reminder of what I look like when I give in to my cravings. My visualization of what I want to look like is my weight at age 17...200 pounds.
This is what helps me get over my cravings. The photo thing may be too harsh for some people, but it keeps my brain on track.