Nice thread! Personally, after making many snaps with the listed method of making snap triggers, I found that putting the epoxy putty into the clothespin first, then putting a nail through the the epoxy putty and having the head of the nail sit on top of the epoxy putty worked best for me. This way, the nail is held straight and in place by the epoxy putty. When I had the nail seated at the bottom of the clothespin, the lack of support caused the nail to start to wiggle after extended periods of time. Having the extra support from the putty really helps with the stability of the nail.
EDIT: Forgot to add, I put the nail through the second bump in the clothespin, rather than the foremost one. I sink it slightly into the epoxy putty so that it is flush with the rest, and then I screw the L bracket over the nail head to ensure it doesn't come out.