It is a hard question to answer because all of us are different. The things you need to consider (keep in mind I am no expert) are the size of your jaws on your release. The bigger the jaws the bigger the loop. You want the loop long enough so that the release doesnt contact the nock on the arrow also. Themain propose for d loops is so you dont torque the bow string when drawing so a little longer loop will give more forgiveness but too long and your draw length will be affected. I usually try to makemine as short as my release allows without interference. They are easy to tie so get some loopmaterial and try a few to see what works best.