Basically it's about eating very high energy density foods like coconut oil, ice cream, sugar, salt, chocolate etc (it was so much fun!) and limiting anything with high water content like veggies, coffee/tea etc and water itself of course. The colour of your urine will tell you if you're dehydrated or not, i think most people drink wayyyyy too much water and the whole "8 glasses a day" stuff is woefully out of date.
For instance i've been eating this way for a couple of months and barely drink more than 1-2 cups of water/tea per day and my urine still is never really that dark and i never feel thirsty/dehydrated.