We tend to buy emergency ready meals monthly and stick them in the freezer. It's only Hubby who uses them though for work when we haven't prepared stuff in advance. He works nights and can�t just pop to the shops like I can in my job if I�ve not brought in a lunch for myself.
Otherwise we buy stuff either on the day or the day before we intend to use it. Cheeses get bought weekly or when we run out. Fruit and veg are bought every couple of days depending on what we feel like having. Milk and bread daily as we need it. Meats on the day or the day before.
We're lucky in that our greengrocers, bakers and butchers are really close to where we live. So, come to that, is Sainsbury's which is the only place to buy fresh fish near to where we live. We used to have a fishmonger nearby - have they died off everywhere else too?
We used to buy everything weekly but never seemed to use it all before it went bad. Also, I like to plan ahead on the menus for a week but sometimes you decide at the last minute that you really feel like something else and end up running out for another set of ingredients anyway.
Monthly has never been an option due to the fruit and veg not lasting that long.