Personalization is an interesting trick: Put something individual on the most common of objects, and it becomes a treasure. It's as true for a hammer set as it is for a watch or robe.
Chances are, your do-it-yourselfer has interests beyond the shop. You can use that to bypass the "Oh, he/she already has one of those" problem. That could mean having a sports-team logo printed on a new toolbox, or a special symbol or phrase engraved on a shiny new top-of-the-line wrench (you may want to check the brand on your DIYer's current wrench -- that matters).
Names and initials, of course, are great crowd-pleasers, too.
Up next, who couldn't use the gift of ideas?