I use a small lanyard or a loop of leather lacing held together with a large bead - just enough to easily slip my little finger through it. I find that by doing this, I can quickly "drop" my knife (A Busse AD, GW, or 3-inch Randall #10) in order get full use of my hand to climb, grab, or hold something, then just as quickly "retrieve" my knife back into my palm when ready with a flip of my wrist. It also seems to prevent my hand from sliding forward onto the blade edge under slippery conditions.
By the way, Gary, thanks again black and tan lanyard you just sent me - very nice work. Now I need to figure what lanyard colors would work best for my new Snakeskin Game Warden LE.
Best to all of you, "Bloody Bill"