Put the fly as close to the stump, log, or rock as you can, and keep it there. In a small open space of water in lily pads or cypress stumps where the bass will not or cannot move far it will usually respond well to the sitting fly. Another method is to cast the fly to where you think the bass are. Let the fly sit in one place for about three to five seconds, then twitch it an inch or so. If you're using a surface or diving fly, vary the twitch from a silent move to an audible pop or bubble.
More noise works best on rough surfaces, and in dark, murky, or densely structured water.
You want to try and imitate helpless creatures or one that's relaxed and moving slightly. Varying the retrieve can help. Rapid fly-line strips of a few inches long up to a couple of feet in length imitates a panicked bait fish such as a minnow. . Big fish can be provoked to attack large big bass bugs that intrude on their territory. Try retrieving a bass bug past some water-lilies where these predators lurk.