This is what I use to do. I plan a meal for dinner, and make enough for leftovers. The rest is packed up and used for lunch the next day.
As far as meal selection goes, I like variety. I use to sit down and make a menu for the week. I usually only plan for the weekdays, and wing it on the weekends since weekdays I have less time to go on inspiration. I plan on 3 chicken meals for the week, 1 beef dish, and one other protein (I do chicken again or egg). Then I think about the actual meals I want, write down my grocery list and go shopping on Saturday.