I fish "Streamer's", in two different ways. Either unweighted, so they are presented just below the water surface, or weighted to fish on or near the water bed. The two major zones where fish take food, is within 2 feet of the surface, or 2 feet from the water bed. Everything else is a Dead Zone.

If I fish them "High", they travel hook down. If I "Low", they are keeled and travel hook up.

Keeling is laying a wire weight on top of the hook shank, and wrapping the weight secure, before dressing the fly. This changes the "Center of Gravity", so the hook will travel through the water hook up. Hook up, helps prevent hooks getting caught on underwater obstructions.

I normally use metal beads, as weight on nymphs, where it is used as a Thorax (not a Head). Helps saves on rod tips becoming shattered for Bead Impact with the Rod Blank when casting.