ZIPPERS Keep these fasteners working smoothly by running a piece of natural beeswax (found in hardware stores) over a zipper's open teeth.

EXTERIORS Leather, of course, is a skin, so keep it happy and moisturized with a leather conditioning cream. There's no reason to treat it with a protectant or a silicone spray. Caught in the rain? Run for cover, then dab—don't wipe—moisture away.

HANDLES AND STRAPS Residue from lotions can discolor and age material—another good reason to keep hands clean. Also, don't overstuff a bag; too much weight can weaken stitching or damage straps.