It's best to perfectly flatten both gluing surfaces to ensure a good bond. I grind most of the tip away, at an angle, and replace it with horn. I use Smooth On epoxy and groove the gluing surfaces with a toothing plane blade. I've never had one come loose. The grinding is done with a hand held belt sander, held in a bench vice. The opposite bow tip is on the floor against my instep so it doesn't move and the angle of the grind is adjusted by where i place my foot and by tilting the sander in the vice until the desired angle is achieved. Once the first one is complete, without moving anything, the second one is quickly ground to match it.
