One thing that works for me is to say to myself "I CAN have that cookie/glass of wine/ chips and dip, but I DON'T want it." It reminds me of how I feel afterwards, it makes me think of the progress I've made. As I get farther along in this lifestyle change, the desire for bad foods diminishes.
Also, on a side note, I've recently started working in a skilled nursing facility. I love working with my clients, but getting old is now absolutely terrifying to me, and it makes me think much more about how I nourish my body.