Yes, don't forget to cut the lip slot immediately after sawing out the bait's side profile, while the lure is still "square". Carving wood freehand requires skill and experience. IMO, balsa is particularly unforgiving because it's so easy to cut and sand. You can start with a block of wood and end up with a toothpick if you're not careful. I use layout lines to define the limits of where I want to shape the corners of the bait. Once you begin shaping, the grain structure in the wood makes it very difficult to judge whether the bait is truly symmetrical just by eyeballing it. Drawing layout lines is tedious work but it allows you to do a majority of the shaping on cruise control, without having to worry about screwing it up.