in that situation i like to bet out around half pot on the flop to make it seem like i have top pair and just want to take it down. in my experience that has gotten decent action from a smaller flush or maybe a re-raise from 2 pair. however, you are not going to get any real action in an unraised pot unless someone else hits a decent hand or wants to bet at it. you may be losing the small bet that was made on the turn, but if you are looking for a big pot i think that is your only hope.