I've been doing leatherwork for about a year now, and I'm still learning knife control. I recently switched to the knife my dad used back in the 70s from the one that came in the Tandy kit. I finally realized that neither knife was really sharp enough, so once I got the knife sharp, that helped a LOT. One other thing I had to do was put a drop of oil in the swivel in my dad's knife. That made it swivel a lot better.
Glen