I used to use these finger slings, but always found them to be a bit fiddly and got in the way when I shoot, so I did this:
Take a length of your fave string, lace or rope and some aquarium air tubing cut into 1/2 cm lengths. Cut 1 piece slightly shorter. This piece goes in the middle.
Use a small flame to narrow both ends of the material, and start fitting it in 3 pieces of air tubing. Sometimes using a pair of tweezers makes threading the material through the bits of air tube easier! You want the bits of air tube to be TIGHT as that would keep everything in place for a long time. If you want to make sure that the tubing never gets lost, heat the ends of the material with a flame and flatten them after you've fitted the bits of air tubing.
Fit one end on and slide up the piece of air tube. Your thumb goes in between the remaining two pieces of air tube. Adjust overall length to your liking and tighten up.
VOILA! Super neat finger sling that's much easier to put on and take off (you only need to slide the outermost piece of tube to loosen the sling, slide one side off your thumb and put the bow down).
What I really like about it is that
it's very secure without having to worry about the slickness of the material used - with the air tube restrainers, I can use the slickest, softest material and it will all hold securely because of the air tubes. And because I can use a much softer, slicker material that won't abrade my skin, I can also use a thinner material, which also contribute to ...
read on:
Another advantage is that without any loops or knots of any sort, there's less possibility of putting sideway pressure on any part of the bow grip ... so besides ease of use and looks, when used properly, it contributes towards more accurate bow-hand positioning.
Hope you like my sling and give it a try one day.
CHEERS!
Edit: P.S. Matt, try a well-stocked Arts & Crafts store. They generally have a range of some of the brightest, snazziest coloured ropes in different styles and sizes. That's where I get my crazy coloured ropes like the one in the photos.