Just did the same thing myself a few weeks ago. I was trying to think of all sorts of ways, pipe clips and all of that stuff, then I had the brainwave of hanging the rods up the way most rod manufacturers recommend. If you use rod bags then most rod bags have loops on the bottom so set a row of sturdy nails equally spaced on your wall then simply hang them up. If some of your rods do not have bags with loops the tie short pieces of string round them to hold them together then hang on bent sections of wire coat hangers on the nails ... Simples.