Amazon prime.
I have things like cat food, toilet rolls, washing powder etc on repeat order. I just worked out how often and how many and they automatically get delivered every two/three months. Saves running out and carrying heavy/bulky items.
Also find a local place that sells stuff just going out of date or is out of date - normally things like tins of beans, soups, crisps etc which are sold at a massively reduced cost and are absolutely fine. Saves us a fortune.
Chalkboard in the kitchen. As soon as you notice you are down to one or two of an item, write it on the board for shopping. When you go shopping just take a photo of the board on your phone - saves actually having to write out the list again.
Check out your local butchers - ours does a loyalty scheme and also do deals on bulk buying so if you buy say 10lb of sausages you get them at a cheaper price per lb than buying just 2lb. I shop once a month, fill the freezer and every time I shop I get a stamp on the card which can be redeemed for a 'breakfast bag' - eggs, bacon and sausages.
Make your own pasta sauce using passata, onions and herbs. Really quick and easy to make and so much cheaper than buying jars. Add a teaspoon of sugar to remove the tartness of the passata and oregano, thyme and garlic for flavouring. Total cost is about 40p instead of over £1.
Hooks and pegs for everything. For keys, bags, coats - have a bag for each of your dc's activities. So easy to just grab the bag in question than to run around the housing looking for 'stuff'. DD2 has two swimming bags, martial arts bag and a kayaking bag. All hung up in the cupboard along with dp's lifeguard stuff. We have designated hooks each for jackets/coats and a shoe rack in the porch.
Storage boxes for under beds - anything not in regular use can go under but even things like clean bedding/towels can be stored underneath a bed.
All bedding goes into one pillow case. So duvet cover, sheet, other pillow cases all get folded up and put in so you don't have to hunt for matching things. Just a box/drawer full of pillow cases with the rest inside.