I used to run a server, and I would say what I put together was rather successful. I don't have the original cfg anymore, but I can tell you what I looked for when I made it, in a do/don't style list :D
- DO use the most impressive maps you can find.
- DO study potential map canidates' layouts to find the best possible mode to associate it with. Linear-styled maps are best for team modes, arena-styled for ffa, etc./
- DO update your maprot every once in a while with new maps. Find a really good map on Quadropolis? See if you can make room for it in your rotation!
- DO act upon feedback. This thread is a great start. Getting a group together in IRC is also a good way to plan a maprot
- DO blend official and custom maps.
- DON'T use a lot of "cliched" map/mode combinations. It's nice to play something other than ac_desert TOSOK or ac_depot CTF every once in a while.
- DON'T use maps with custom media unless it's a custom map server. ac_egypt is all pretty until it's turned into a gray mass of "missing content" textures.
- DON'T use crap maps like riflecamper. EVER. I will shank you with a raw salmon if you do.
- DON'T pair large maps with small player sets and vice versa. Sitting in ac_sylang for 10 minutes after you die because some idiot thought it'd be good idea to make a group of 3 rotate to that map on TSURV is NOT fun.
- DON'T forget to throw in some fun modes like PF, particularly for smaller groups. There are times to be had with these neglected modes.