Exercise more so that you sweat out the excess. Also, Gatoraide, or other drinks with electrolytes seem to encourage your body to shed some water, but don't overdue them as they are high in potasssium.
monitor your diet not interms of eating less but watch what happens with your body when you eat either wheat or dairy products. Both of which can make me bloat and I notice the difference when I cut back or cut out both completely. Not saying this is what causes your retention but its something to think about