I have been using the A+b epoxy putty, comes in white and black and I believe you could mix the two for different color affects. I care down the end of the bow as if I were installing horn nocks and form the putty right on the end of the bow like clay. My putty takes about 8 hours to fully harden, I don't like to work it until it is fully hardened becuase it plugs up the tools real fast. I don't get real fancy with the long tip sticking out, I think it would break off it were bumped, just forming it to a slightly rounded point seems to be pretty durable and can stand a little banging around.
