One BB shot above the top fly is usually about right but adjust to the conditions. Use an indicator five feet above the split shot. Think small nymphs. Most fish will be taken on bugs sizes 18 to 22. Wide-gaped hooks like the Tiemco 2488 will improve your percentage of hookups.
Favorite patterns are olive pheasant tails, hare's ears, red serendipities and red disco midges.
Thin, sparse nymphs are best. This style of nymphing will produce hookups, but getting these big, hot fish to the net is difficult on the best of days, and a series of lost fish can be frustrating. Fluorocarbon tippet is quite slick, which causes the split shot to slide, so place it immediately above a knot. This type of heavier rig will still get results, and it gives fly fishers a more realistic chance to land big fish. These fish see a lot of flies in the course of a season, so they get very drift sensitive.