A simple corner brace for aligning small pieces of wood while gluing. You will need some kind of clamp to hold the wood in place while the glue sets, but this will help keep things square.

This is similar to others but I added some lips on the inside and outside edge to keep things square for small pieces of wood.

Update:
I added a second version with knobs. The idea is that you can use the knobs to hold rubber bands to secure the clamp to to job. I don't expect this to be a strong hold but it might be enough to free your hands to grab something. I added this because I could have use this as I didn't have any clamps. But I have plenty of rubber bands. Everyone has rubber bands. :-)

After testing I changed the orientation of the knobs, they should work better now.

Note: The knob version requires supports.