Though this might be an area you or your partner might be self-conscious about, this is an erogenous zone you should try to take advantage of.
A great position to caress the stomach is from behind your partner. Sit behind and have your partner lean back on you. Not only will you have access to the chest, but the closeness of the position should also help your partner to relax and let go of any feelings of self-consciousness.
To really light her fire, trace your fingers from the top of the tummy to the top of her pubic mound, over her hip bones, and back up again. It won’t take too many of these teases before she’s grabbing your hand and pulling it down just a little further.