I like the Christmas ball stand from ChessmondN. I have one printed out and assembled, but it wobbles in all directions because the gap in the base is bigger than the foot. Especially in the X-direction. In the Y-direction there was only slight wobbling. So what to do? One solution could be to glue both together. But I am not a hughe fan of gluing. I like the idea that it is easy to assemble and disassemble and therefore can be stored flat. So I thought about it and remembered techniques of Japanese carpenters and woodworkers, they use very often simple wedges.
So I switched on freeCAD and generated a simple wedge that is pushed into the gap and stabilizes the tree. The tree is now easy to move and the fix is nearly invisible. Ta-da, mission accomplished ;-))