1. Carb deplete for 3 days prior to DNP because DNP will take a good 2-3 days to deplete the body's glycogen stores before it can efficiently burn stored fat.
2. Once on DNP eat an isocaloric diet (33% prot, 33% fat, 33% carbs) and keep the calories at around maintenance level. Restricting carbs will put the body in a state of hypoglycemia and can be dangerous to the health and also the mental well being. DNP also mimics insulin in that it shuttles glucose into the cells in the absence of glucose. This is great for fat burning, but when carb intake is too low the blood glucose can be at dangerously low levels as well. a more experienced user can switch up this ratio a bit. Either way it won't make a huge difference because it's mostly about the total calorie consumption.
The least effective form of dieting while on a DNP cycle is a fat diet, or ketogenic diet, but the high amounts of fat helps to slow gastric emptying, so you feel more satisfied for a longer period of time