I do it week by week.
Write down 6 meals (seventh night I either cobble together something out of what we've got leftover or get a takeaway). I also write down 6 lunchy things for me and 6 for DS.
Write down all ingredients needed.
Buy them!
Easy peasy. Saves you a fortune, too. And if you shop online you can get it to 'remember' your orders.
Current weekly meal plan:
Monday - Teriyaki salmon, soba noodles & stirfired greens
(Lunch for me: Halloumi & salad; Lunch for DS - Halloumi toasties)
Tuesday - Veggie curry & roti breads
(Lunch for me - tuna & cannelini bean salad; Lunch for DS - tuna pasta)
Wednesday - Prawn & veg stirfry & rice (Lunch for me: Avocado & salad wraps; Lunch for DS - Macaroni cheese)
Thursday - Roast chicken breast, roasted veg and baked sweet potato
(Lunch for me: Omelette & salad; Lunch for DS: Eggy bread & baked beans)
Friday - Grilled tuna steak with baked potato & steamed veg
(Lunch for both me and DS: Soup & bread)
Saturday _ Curried chicken, rice & peas, fried plantain
(Lunch for all: Pizza & salad)
You get the drift...