Dima's suggestions are excellent. I would add, though, that once I have a good handful of pieces to work with, I will pick one or two a day to really beat on -- artistic, technical traps, whatever -- and do it. However... I try to keep a goodly repertoire at least functional at all times (currently only eight pieces to playable to an audience quality, but that's enough!) and to do this, I make sure that each of them gets played at least every other day, and if anything sticky show up (it does) that piece goes on the beat on it list. I find that if I don't do this, anything that wasn't rock solid tends to get a bit messy.
Also -- I try very hard to vary the sequence in which I work on pieces unless there is a specific reason for a specific sequence.