How to trim your waist and tone your stomach?

My waist is like 26 inches, which is okay, but considering my relatively small bust I'd like to take off a few inches. And tone the general stomach area. I do cardio work- running 3 times a week (30 minutes twice and an hour once), yoga and I occasionally use dance and pilates DVDs. Any other advice? (I've wanted to do corseting for some time, but I sadly don't have the cash to spend on a good corset at the moment).