While screwdrivers may look like pry bars, chisels, punches and scrapers, they should never be used for such purposes. A screwdriver is most effective when its blade is straight, balanced and sharp. Misusing yours will keep it from performing best when you need it to do what you bought it to do...drive screws. Also, be sure that the handle is clean and free of slippery oil or grease.
Never begin sanding on the wood of any carving project until you have completely finished carving it. The small particles of abrasive that lodge in the grain can dull your carving tools fast, and can quickly destroy all the benefits of using good sharpening equipment and techniques.