I blogged about this yesterday -- I finished 2 WIPs and was prepping them to send to an editor. I likened this to doing the dishes once we've finished the feast. It's a mundane, annoying job but it has to be done.
What's involved in your 'final prep' of a manuscript? It doesn't matter if you're prepping it for a contest or an editor or publication -- what are those little gotchas that you always look for and once they're 'fixed' you can breathe a sigh of relief?