I agree with the comment that you should get a bigger belt. I picked up some great belts at Anthropologie. They were wide, woven and completely adjustable and well priced. Good luck!
Wear a thicker belt that has more texture! If this is an American Apparel dress, the fabric itself is pretty simple and doesn't have a lot of texture/visual interest...so needs some pop! That color will go well with anything, which is good!
This dress looks very box-like. You should try a tighter belt to accentuate your figure (by bringing in your waist). A thick, brown, leather belt would be cute!
ya I was going to say exactly what the person below did. black tank underneath and wear a thinner leather belt. i'd also lose the peep toe shoes and pair with some wedges or ballet flats