Supermarkets and kitchen shops sell small screw top plastic boxes. Some clip lock boxes can also be found in smaller sizes. Old 35mm film containers will store about 4 or 5 of the smaller dies.
Personally I avoid wood. I’ve seen too many old tools go rusty due to moisture in the wood. A much better alternative is a plastic box lined with closed cell foam. You can easily make the cutouts in the foam for the dies with a pipe. Even a piece of suitably sharpened plastic pipe will cut foam. Cheap sources of foam are things like gym mat tiles, often sold in Aldi/lidl.