A common rig I use on the Clinch is to fish a #20 brassie with a #20 or 22 zebra midge about 12 inches below the brassie. A brassie does a very good job imitating midge pupae and the zebra imitates the larva. This rig has been very effective when casting to rising trout.
If I am casting to rising trout I will set my indicator so that the brassie is about 12" below the surface. If I am blind casting, I set my indicator so that my zebra midge is bouncing on the bottom.