To determine the appropriate size for cabinet pulls, consider the size and scale of your cabinets and drawers. A general guideline is to use pulls that are about one-third the length of the drawer or door. For standard-sized cabinets, pulls that are 3 to 4 inches in length work well, while larger cabinets or drawers may require pulls that are 5 to 7 inches long. For a more customized look, you can also mix and match different sizes to suit specific cabinet dimensions and design preferences.