I plan my food the night before and adjust my journal through the day. I have entirely too many frozen portions of whatever that work if I change my mind too. Usually my calories for breakfasts, lunch, dinner, and snacks stay consistent in their allocations.
Lunch is always 1 cup of some kind of homemade soup that I pull out of my freezer, for example, and my homemade frozen dinners are around 250-350 calories, but they're all so different. The dinners are there when I'm lazy, but lately I've been cooking so much that I've had to give away food because I don't have enough room!
I have a calorie goal and keep track with the My Fitness Pal app. I limit junk foods and use portion control.
One thing I do differently is not count the calories of plain fruit and vegetables, for examble, baby carrots. I do count a potato or canned pineapple (packed in plain juice.) I use alternatives sometimes to deal with sugar cravings, ie: celestial seasonings cinnamon apple "tea" has no calories but tastes yummy.
I'm just starting out again (for like the millionth time) but what's worked best in the past and so far this time is planning out all my meals a week in advance and plugging it in to myfitnesspal, if anything changes I can easily edit it. This also makes grocery shopping easier.