Here are the basic sets of rules recommended by experts:

Method of Treatment

As you wake up in the morning before brushing teeth, drink 4 x 160ml glasses of water.
Brush and clean the mouth but do not eat nor drink anything for 45 minutes.
After 45 minutes you may eat and drink as normal.
After your breakfast, lunch and dinner do not eat nor drink anything for 2 hours.
Those who are old or sick and are incapable to drink 4 glasses of water at the beginning may start by taking little water and gradually increase it to 4 glasses per day.
What a lot of people do in the morning is go straight to the coffee pot, but coffee actually dehydrates the body.  If you don’t level out your water intake you could go through the day dehydrated.
CBS reports that while most people know perfectly well that water is the way to go, up to 75 percent of the American population fall short of the 10 daily cups prescribed by the Institute of Medicine – which, in medical terms, means that most people in the U.S are functioning in a chronic state of dehydration.
“60 percent of our bodies is composed of water, 75 percent in our muscles, 85 percent in our brains, it’s like oil to a machine,” explained Dr. Roberta Lee.