Photo from Lowe's
With a few pebbles for game pieces (some dark, some light), a piece of slate tile, chalk, a little white paint, and a permanent marker, you can make one of these natural-looking Tic Tac Toe games and gift it for the holidays.
Lowe's provides step-by-step how-to instructions on their site. It's pretty self-explanatory, but you may find their suggestion for no-slip felt pads and a clear topcoat helpful.
Can't you just see this pretty Tic Tac Toe playset out in Grandma's garden?