When it comes to plastic exterior trim, hand-driven trim nails with painted heads are the fastener of choice, but hammer marks can take a real toll on the installation. Protect-O-Caps help protect both the nails and the trim. The polyurethane caps — with the help of included shims — fit on many 16- and 20-ounce hammers. Some nail manufacturers include the caps in boxes of nails, or you can buy them separately for about $2 apiece. We got the best results when we changed caps as soon as their faces got a little chewed up. Protect-O-Cap, 803/370-3329, protectocap.com