Howard, patience is the #1 tool for a wood bow builder. If you add less bow length or higher and/or longer draw lengths than patience is more critical. Once you get your stave to floor tiller stage be conscious of every scrape or rasp you take off, exercise the stave well between wood removals but only is small incriments and never draw past final draw weight of length especially early on in the process.
Also with a stave that might be on the borderline of your abilities allow the stave to tell you what it wants to be instead of trying to manipulate it into a predetermined design.