I cut my 3d ornaments from hardwoods such as maple, ash, walnut, poplar. I think poplar is the easiest. Balsa would be too fragile. I cut with a FD Polar 5 or PS Super sharks #5. Typically, I use 1-1/4" thick material. You have to be patient cutting thick material and go slow.
These are some 3D ornaments that I have posted before and clamps I use.