For the "Generic HandyPerson", an inexpensive LED headlamp is wonderful. Utility knives, whether the X-acto type, snapblade knife, or the "normal" utility knife that we will usually use are another good one. "Shop" scissors can be mighty handy. As a gag stocking stuffer, a roll of duct tape and some bailing wire are good. The magnet parts bowl/dish is always useful for a DIY'er or anybody who works in a shop, not quite so much for a tradesman who works on jobsites.
A snazzy small case with some ear plugs. Cool looking safety glasses. "neck cooler" bandanas/wraps or doo-rags can make good stocking stuffers as well. Just don't go with clothing items that are "branded" for your own company if you have one, or at least if you do include something else. The boss giving promotional merchandise to employees as gifts just screams "cheap ***". A couple rolls of the Velcro Wrap-ties are always useful, if not especially "gifty".
One handed clamps (available in promotional sets this time of year) are almost always appreciated.
