You can see at the end of the day, if you feel that you've eaten well, what balance of macronutrients you've had - protein, fat and carbs. You might notice days when you feel like your food choices have been more successful and you've felt satisfied. Then, notice the balance and see if you can replicate that balance again.
I keep my eye on fiber. If I eat more fiber, then I feel more full with fewer calories (fiber is in cereals, high-fiber crackers or breads, and fruits and vegetables).