Remember that our bodies are different, and finding clothing that best fits your body shape can go a long way.  Here are a couple resources that provide some useful tips in how to recognize what will work best for you:

Spanx Shape Wear:

http://www.spanx.com/home/index.jsp

Maidenform Shape Wear:

http://www.maidenform.com/shapewear

Keep in mind there are many brands out there with a great variety of styles of shape wear, so look around and you can find the right match for your body and for the outfits you plan to wear.