Dress up screw holes.

Buttons. These mushroom-capped plugs have decorative domed tops that stand proud of the surface.
End-grain plugs. Because you're not matching face grain to face grain, these plugs are more obvious. End-grain plugs can be cut from standard dowel, and require no special tools.
Face-grain plugs. With careful grain matching, these hide holes best. Buy them premade. Or for best color match, cut them from scrap project stock using a plug cutter in a drill press.
Different-species plugs. To really make a plug into a decorative element, try using plugs from contrasting species (walnut in oak, for example). For flush-fitting plugs, use a flush-cutting saw to trim them off (see photo above). Or use card stock with a hole in it over the plug to protect the surface and use any fine-tooth saw. —from the WOOD® shop