We always have milk and bread in the freezer, so never need to do a top up shop, because we'd never only come back with just the milk/bread we need
Reduce amount of packaged snacks and alcohol you buy
Add a tin of green lentils, and half a bag of frozen base mix (diced carrot/onion/celery) to any mince based meal (spag bol, cottage pie) to bulk it out and make 2 meals from 1 pack of mince
Shop at around 8pm to get the most yellow sticker items. Freeze anything that can be frozen.
Make use of Too good to go and Olio apps
Buy everything you can second hand from vinted, charity shops, car boot sales
Sell stuff you don't want
If it takes less than 30 min to walk it, don't drive
Make sure you're getting at least 4.5% on your savings
Put money in your savings as soon as you get paid
Can you get a side hussle? Delivering leaflets, dog walking, proof reading?
Can you learn how to cut your, DH, kids hair?