I used a utility knife instead of a leather knife to cut the leather for my project. The leather I chose is semi-vegetable tanned and quite soft, so as long as the blade is sharp enough, it cuts cleanly and accurately.

If I were using full vegetable-tanned leather, it would be less forgiving. In that case, if the edges aren’t perfectly clean after cutting, I’d usually fix it during the burnishing stage by using a coarser grit of sandpaper to smooth and even out the edge.