Chisels make easy work to make holes in leather. A single prong does just that ...1 hole at a time. If you can afford to add a 2 and a 4 prong, it will help you keep your line a little straighter and your hole spacing much more consistent. I use all three. 4 prong for long straight sections, 2 prong for bends and round edges, and the 1 punch when I have a gap between 2 holes that is just too wide to leave without a hole.
Someone just recently shared this link. It may be helpful.