One of the leech patterns that I tie up for myself most often is quick, simple, and uses marabou. This pattern is very basic, a two toned tail is the most complex part of this fly. The zero gravity dubbing makes for a fantastic durable body. I often make stainless steel brushes using the dubbing and crank these leeches out fast.
This color combo is one of my favorite, along with crayfish orange, black, and I have even had a couple lucky white and tan ones.
Hope they fish as well for you as they have for me.
Hook: Gamakatsu B10s size 2 - 4
Thread: Semperfli Waxed thread 6/0
Bead: Brass Gold Cone
Tail: Whiting Farms Superbou
Flash: Krystal Flash
Body: Zero Gravity dubbing from Snake River fly