I don't have a set format or list. I actually use 1/2 of a sheet of 8x11 paper from my recycling bin! One half has my menu for the week and the other half is my grocery list I need (after I check my pantry and freezer which is how I start my menu list).
For flexibility, I look at my calendar when doing my menu so I don't have a complicated meal on a day when we have evening activities. And I don't plan a meal for an exact day *unless* necessary. I just plan 6 to 7 meals and can make them anytime during the week.
Note: I only do this for evening meals. We are gone most days during the day and when we are home, we eat leftovers or sandwiches for lunch.
I try to include protein/meat, veggie, fruit and some sort of good carbohydrate in each meal.
Here is an example of my weekly menu (remember, I don't usually assign a day to a meal for flexibility) and I just write it on paper and post on the fridge.
Chicken tacos, black beans, cheese, lettuce, tomato with watermelon
Roast beef, carrots, onions and a tossed salad, buscuits or bread
Grilled cheese and tomato soup with grapes and apple slices
Breakfast for dinner: scrambled eggs with cheese, sausage or ham, toast, strawberries or canned fruit (if need be)
Grilled chicken legs, tossed salad, sweet potatoes, apple slices
Turkey burgers, sliced tomatoes and pickles, fresh fruit, cottage cheese
Macaroni and cheese, green beans, frozen fruit or fresh fruit
The roast and chicken tacos are crock-pot meals for me, the grilled cheese and breakfast are my time-saver meals on busy nights and macaroni and cheese is something I can make the night before and then put in the oven to heat up after work. I make enough so we have leftovers for lunches. As for my shopping list, for example, I have the roast, chicken legs, ground turkey and ham and sausage in the freezer. I may need to buy fresh fruit and veggies, eggs and cottage cheese. I have tomatoes from my garden and pickles in my pantry. I keep plenty of pasta and cheese in my pantry and freezer. I may make a loaf of bread or get one from the freezer. I check this over before I make my menu. After I make my menu, I make my shopping list.
Hope this helps!