I've competed for about 4 years and done 7 shows...and I'm currently training for one myself, so I can tell you what I do.
Assuming the show is on Saturday...
The previous Sunday I'll begin carb depleting and sodium loading, simultaneously. Try to keep carbs under 50g/day...Eat lots of beef, eggs, chicken, tuna...and I add salt to my eggs and other foods, but I don't go overboard with it.
I do that for 3 days.
Then on Wednesday I begin carb loading and sodium depleting...I try to take in 0mg of sodium per day. It's really not too difficult b/c I only eat two types of foods: oatmeal w/splenda and baby food (you can find some baby food with 0mg of sodium, like squash or sweet potatoes...) Since I'm 24 and single, it's always fun to head to the grocery store and toss like 60 jars of baby food at the cashier.
I eat every 60 min or so, trying to take in 30-40g of carbs each time. I drink distilled water too.
Through much trial and error, I have found that I lose alot of water that way (5-9 lbs). At the same time, for my last show I noticed that even though I lost a good amount of water, I looked a little smooth and I think it's b/c my muscles needed some sodium to tighten up.
So this time I plan on tweaking it a bit. Everything will be the same, but on Friday afternoon/evening I will slowly introduce sodium back into my diet and go back on regular water, while carb depleting again. Same goes for Saturday morning...I find now that I look the best after about a day of carb depleting.
Hope this helps
I too would love to hear other people's thoughts on this, as I'm always looking for better ways to get shredded.