Add protein to every meal. Recommend amount of protein to maintain muscle is between 0.7g to 1g of protein per body weight in pounds. For example, if you weight 200 lbs, you should eat 140g to 200g of protein per day. If you eat 3 meals a day that is about 47g to 67g of protein per meal.
No snacking. Just eat full meals.
Eat your vegetables. Aim for half your plate of a variety vegetables.
Include 1 portion/ serving of carbohydrates. Just don’t eat 3 to 4 times your portion size. This may vary depending on your goal, but half a potato, or half cup of rice is a good start.
Don’t skip meals. Eating more increases your metabolism.
Drink water, and not juice or soda.

Check out Josh Hillis and Dan John’s book “Fat Loss Begins on Monday” for advice on fat loss.