I'm surprised so many people pre-plan... My food choices and quantities vary based on how I am feeling, but I have never had much issue logging throughout the day and sticking to my calorie budget.
My situation is unusually stable, however, being at home everyday with small children. We have the same lunches every week and the same breakfast selections, and I make a dinner menu every two weeks. Nothing too adventurous or different that would throw me off, and the occasional meal out is easy enough to log.
In my experience it isn't the preplanning that makes the bigger difference (except in buying groceries and having enough time to cook and clean up each meal) but rather the logging, itself, whenever it is done, that makes ALL the difference in the world in how I lose weight and how conscientious I am of what gows in my mouth.
If I had vision problems I wouldn't assume I could just go without glasses and be okay, the underlying problem is still there without surgical correction. For me, my eating is the same. I have a problem with overeating if I do not have written accountability. In lieu of surgical correction I can't just stop my food logging and expect to be okay - it takes constant, daily vigilence to stay healthy and manage my weight and that is not something I am willing to gamble with.
However we do it, I am just SO thrilled to have so many fellow food logging calorie counters here. The real world tends to think I'm a bit nuts