Download a food tracking worksheet or use a lined notebook to create a food journal. Evaluate your food habits by writing down everything you eat on three weekdays and one weekend day. During those four days, write down how you feel and what you're doing while you were eating.
After the initial four days of entries, evaluate where your diet is lacking, and attempt to address those issues. Maintain the food journal for several months as you work on your goal. Common goals include controlling hunger and reducing caloric intake. Make the food journal a daily habit by writing the date in it first thing in the morning and keeping it with you at all times.
If you are trying to control hunger, enhance the daily entry by recording how many meals you ate throughout the day and how many ounces of water you drank. Keep a log of the type of foods you are eating and if they are nutrient dense or empty calories.
If you are trying to reduce your daily caloric intake, then make a note of portion size, calories per meal and your daily calorie goal. At the end of the day, write down how many calories were actually consumed.