Best way to lose weight in stomach and butt?

I’m not way overweight, but I carry more than I’d like to in my stomach and rear… I’m trying to lose it, eating a lot less, exercising. From the chest up, I’m getting bonier, but my tummy and butt still jiggle, and are the same measurements they were to begin with. I want to lose the weight in those two places, not my shoulder-collarbone region. Is there any way to get my body to respond the way I want it to? (Like, I do crunches, but should I be doing more? Are there foods that will tend to leave their excess in those places that I should avoid? Or do I just have to deal with how my body is behaving?)