1) Cut these from thick construction foam. A hot knife will make the work easier. If you are making rocks, the edges can be less uniform and more jagged.
2) Paint the foam with latex paint and let dry before spray painting or the foam will melt.
3) Paint a light brown or tan for the center and darker browns for the edges.
4) Draw or spray rings on the tree slices if desired.
5) Rocks will need grays and browns and black.
