My go to combo is a wiggle tail, rufus, or leech as the first fly, then a Prince attached with 18"-24" or so of tippet to the hook bend of the first fly for the point fly. What I've noticed over the years is that at least 80% of my fish come on the point fly, usually a Prince. In one lake virtually all Rainbows take the first fly, the streamer, and the cutties take the point fly and never the streamer, but that's the only exception that comes to mind. Sometimes I wonder if using the streamer is worth the effort if they are keying on the Prince. I also wonder if the streamer acts as an attractor and they end up preferring the nymph, and, if using the hook bend to secure the second fly tippet rather than attaching the streamer with a longer tag from the blood knot would give better action and results for the streamer. What do you do, and what have you found to be the best two fly rig?