I was taught to finish the ends this way.
Back stitch twice.
Then go half way through the third stitch and out between the two pieces on both sides.
Both ends should come up between the pieces of leather.
Tie the ends together with a simple knot and pull tight, do this twice.
Snip the ends close to the knot, leaving maybe .25 inch.
Tuck everything down.
Everything is hidden between the pieces of leather. No need to singe the ends.