[dsraven]

I personally use pieces of plywood with the paper stapled on the ends( not on the surface that touches the parts getting sanded). It doesnt bend like some foam backed boards do. I find it hard to not push down too much so this way it is harder to bend the sanding board. Pieces of dowel work well for soft body lines. Different colors of high build make it easier to stop sanding when you go through the current coat. If you are sanding blue primer and start seeing the previous color then you are through that coat and need more sprayed on before you start sanding through to metal. Scuff sand the low spots before spraying to ensure they get a tooth.