A six or seven weight is a useful general starting outfit, adjusted for the fish and cover. Carry a small baitfish streamer, a lightly weighted shrimp and a surface pattern for obvious feeding on top. Keep hooks sharp.
Cast past the activity so the fly can settle before it reaches the fish. Try short strips with a pause, then a steadier retrieve. If fish keep rolling but nothing takes, work a little deeper instead of repeatedly laying the line over them.
Keep the rod aligned with the line when the take comes and strip into the weight. Manage loose line before the fish reaches the reel. When a fish jumps, avoid holding the rod rigidly against the movement; stay responsive and keep the pressure controlled.