One of the big things I use my 3D printer for is to make tools that make dealing with one hand a little easier. Soldering 2 wires is a good example of this. So this is what I came up with:
Reverse tweezers? Color me extremely interested, I've had more than one occasion where I could use two of those.
Keep in mind that whenever you use something like that, in my world you have to have one hand behind your back. Anything with a ball joint is a two handed job.
Cross lock tweezers can be very handy but the one caveat is concerning the angle of the jaws. On many versions they are not parallel which means, effectively, they can only hold one thing. For example if have two wires of the same size the one closest to the tip will hold the jaws open too far to grip the second.
Other than that, they are very nice, and with a base like this one, versatile. They are commonly used in jewelry making.
Ceramic jaw versions are very nice if you have to heat something a great deal, the all metal ones can lose their temper but these will tolerate an enormous amount of heat, even from a torch.
[EDIT: Fixed butchered sentence (due to inline editing) and fixed butchered formatting (due to UI’s unfortunate interaction with the iPad)]