I do it after the fact. I'm aiming anywhere from 1300-1600 calories per day (depending on if I exercise and how my weight loss has been doing). Then when it comes to meals, I just mentally divide my total calories into 1/3's, then try to eat that amount at that meal (I eat at my college's cafeteria). I've been calorie counting for a while, so I can guesstimate pretty close to what something will be. Once I get back to my dorm room, I log the food using an online food journal and *most* of the time I'm pretty close to what I guesstimated in my head. If not, I just have to cut back on the next meal.
If I know I'm not going to be around a computer for a while, I go ahead and jot it down on a napkin or in a notebook, so I won't forget anything once I put it into the computer.
I personally love calorie counting and food journalling--nothing is off limits, as long as you count it (I do try to eat my fruits and veggies though). And I've lost 30 lbs. so far, so something must be working.
