Most will do the trick. The key is simply keeping a consistent angle and moving to finer and finer grits. Some also strop their blades using jeweler's rouge and a piece of leather. I don't find it particularly necessary, though it does help. I use Slick Tricks, and touch them up by using one of the Smith's handheld carbide sharpeners (similar to an Accusharp). Works well enough by using very light pressure.