Print your set lists in type that is large enough to read when you're onstage. Someone else mentioned this in another thread, and it resonated with me, because I had recently made the mistake of printing them too small; they were fine when I was sitting in my office looking at them, but under stage lights when the set list had to be placed in an inconspicuous spot, they were so small as to be useless -- for me and everyone else in the band.