I am a typical Grandad, have to fix all sorts of stuff for the grandchildren, so have to hold so really queer stuff (plastic fairy with broken wings!...).
One gizmo I find useful is a very large right angle bracket, about 4" in all directions but with a 2" diam hole in the centre of one face. So I can clamp things down flat with the clamp going down through the hole.
The other things I am about to make are a pair of extension jaws for tool makers clamps out out of 1/8" gauge plate which will be screwed to the sides of the conventional jaws. The extensions will overhang the jaws by about 2" and will have a variety of business ends. So in use they can be used as needle nosed pliars, but with the ability to be clamped to my vice angle plate. Once I have the holes drilled and tapped into the sides of the clamps, I could make any sort of ends, such a 1" diam "hole" between the jaws for holding such a thing as an egg cup.
Frank