When do you fill in your food diary?

I fill my main meals in first thing so I can plan calories etc. I allow myself left over cals to fill up with snacks etc. If I do more excercise than planned in the day then I add more veggies to dinner or a handful of nuts to eat them back. I used to add all planned excercise at the beginning of the day also, when I used to work out in the evnings but if for some reason I couldnt do it i'd go over my calories for that day so now I work out in the mornings I can plan much better. Throughout the day I do tweak foods slightly but generally stick to my plan.

As soon as I can, so that I don't forget what I ate...