When we lived in the States, and thereby lived by the American clock/calendar, I made a weekly menu plan. I planned what meal we would have on what night, and keep a running list of the ingredients needed for those meals to organize my weekly shop. I would shop once a week, and that was it. It worked great!
I highly recommend keeping a weekly menu, and making a shopping list based around those meals. However, I’ve had to tweak my menus to fit our flexible lifestyle. Our life now consists of last minute invitations, constantly changing plans, and a functionally empty calendar, yet weeks that are full to the brim of activity and appointments. I’ve lost count how many times at 3pm we’ve gotten invitations for an impromptu dinner or coffee date that night. So, making a rigid menu plan mapping out what food is eaten what day doesn’t work for us anymore. However, I do still make a menu, I just decide each day what will be made, usually around 3pm is when I decide. Unless I’m making something in the crock pot.
I tell you all of this to say that even of you live a very fluid lifestyle, you can still save money and time by planning ahead. I have the ingredients for 7 dinners in the house, but I can choose which days I make what. Thus allowing for last minute changes.
The last piece of advice is stick to your list! If you make a shopping list, use it! Novel idea, right? Try to avoid buying items you don’t need just because they are on sale. And shopping for the week without a list at all always leads to forgotten ingredients, which leads to more trips to the store, which leads to inevitably some kind of unneeded impulse buy.
What kind of planning do you use for your groceries and meals? How has it changed over time?