If you really want to make changes in your diet, nothing can help you more than writing down everything you eat for a few days or a few weeks. If you honestly and religiously record every morsel you put in your mouth (yes, including that handful of M&Ms your friend offered you this afternoon, and that extra pat of butter you snuck onto your potatoes), it'll reveal not only what you're actually consuming but also a lot of other clues to your eating habits. You'll find out what times of day and what kind of events trigger your cravings; you'll see in black and white whether you need to add more vegetables to your diet; you may be shocked at how much sugar and fat you are eating without even realizing it. And having all this information laid out in front of you in a food journal is a great motivating factor - you're more likely to make changes when you can't hide from the truth. Even if you think your eating habits are okay, you should keep a food diary now and again, just to make sure (you'll almost always find room for improvement).