When I am preparing to go food shopping at the weekend, I will do a rough plan of dinners for the week based on what's in, what the plans for the week are (activities, travels, weather etc) and what extra ingrediants I need to get for that plan.
During the week, I will think the night before about dinner the next day, unless I am totally wiped. So I may have to get things from the freezer, I try to peel potatoes or prep veggies the night before so I can just start cooking when I get in from work. Or I may even put something in the oven and set the timer so its' ready when we get in.
I tend not to worry that much about breakfasts/lunches - I will have the essentials in, DH makes his own sambos, DD changes her mind constantly so we do that the night before, and I make my salads. Weekend lunches we would have plenty of things in to make something.
My general plan is something along the lines of:
Sunday - a roast or dinner that needs prep work and stirring, as I have time to do that. But tried and trusted favourites usually.
Monday - a dinner that I make on Sunday (when making Sunday dinner, I do a double batch of a Monday dinner and freeze half), just needs heating of a sauce and cooking of rice/pasta, or taking something from oven like lasagna. (Spag bol, chilli, curries, lasagna, cottage pie, fish pie etc).
Tuesday - generally some kind of chop, potatoes and veggies dinner - I buy some meat/fish fresh at the weekend for this.
Wednesday - something fast for DD between getting in from school/work and getting back out to sports club training. DH and I eat later, usually something from freezer that 1 cooks while the other brings DD to training.
Thursday - either something really easy (e.g. pizza using ready-made base, grated mozzarella and grabbing toppings to suit; chicken fajitas; a stir fry that I've prepped ingredients the night before) or a "Monday dinner" from the freezer.
Friday - a super easy dinner (freezer, M&S ready meal etc) or a takeaway usually.
Saturday - something nice for DD that she will eat, and later on, DH and I cook something nice for ourselves and relax about doing it. We occasionally go out, but Saturday is "our" night. Often a curry feast (so a couple of decent curries from scratch and maybe a side dish or 2, or even HM naans - leftovers will be frozen so no waste), or fresh fish (good fishmonger is open on Saturday mornings), or steak and HM chips. Or a night for experimenting with recipes.