All Great tips posted above. What I've always done and seemed to work is this....
I never really salt my food heavily or anything, so on the last week before contest prep, I just stop salting the things I normally salt, I don't do any sort of wild sodium increase or depletion or any method.
Water, I keep it high (2-3 gallons per day) alll contest week, but on the friday before the show, I drink usually 1 - 1.5 gallons, until 6 pm, then at 6 only sips when thursday.
Saturday (show day), only sips when thirsty as well.
This is what's always worked for me, its nothing wild or drastic.
I've used Taraxatone before - didn't really see anything very special.