Online delivery shop once a week, you don't get tempted by the "offers" in store
Breadmaker - family of 2 adults, 2 basically full sized teens, x3 love bread, so just make what is needed as and when, virtually no waste
Milkman - considerably less popping out for milk, when you inevitably get more than just milk
Freezer has bags of vegetables, sweetcorn, peas, broadbean, green beans, so you use just what you need for that round of dinner
Befriend an allotmenteer! - at the moment we are getting boxes full of allotment veg, only really need lettuce and some fruit - although apples and pears are covered, unfortunately I don't know anyone with an orangerie full of lemon trees but I am on the look out!
We have a cinematic set up at home, and we haven't been to the cinema for so long, nothing worth the trip, and the teens are into more acting films there is a huge back catalogue they want to see, we have caught up with fairly recent releases on sky movies, so that should see us through most of the autumn/winter/spring
Read the books you already own!
Having a huge declutter and realising how much stuff you buy is more impulse than requirement, saves purchases in the future.
If you do get tempted, put items into you online basket and wait at least 24, preferably 48 hours before "buy now"
Saying this there are huge expenses you can't cut back on with teens, namely anything to do with their education. And we will in the not too distant (hopefully) be having to support one, then two, university rents and expenses, and all the above is pissing in the wind compared to that!