Sanding, if done, should be after all edge tool work is done. The sandpaper leaves grit behind that will quickly dull your tools.
Hand planing a timber isn't too bad, especially if you start with timbers from a bandsaw mill. If you really need to save time, I expect that doing the primary planing with a power planer, and following with hand planes will be the quickest combination, especially in hardwood timbers, but I've never done it that way...
Dan
