Most weeks I buy fruit in a plastic bag. When the bag is empty, I rinse it in hot detergent water, dry it over a tumbler and reuse as a sandwich bag or a freezer bag. I haven't bought plastic bags for a decade. Any bigger bags are used as bin liners.
I have about 20 cotton fabric dish cloths. I use a new one every day, the used one is thrown in with a regular load of washing, so no J-cloths.
I buy large loaves of bread and freeze half wrapped in plastic, so they don't go stale.
I buy 4-pint containers of milk, decant them into empty sterilised 1-pint containers and freeze 3 of the 4. It saves about 50p per pint and cuts waste (plastic and rancid milk).
I use any waste paper & cardboard packaging to light the woodburner. Avoids the need for firelighters, and means I create less rubbish for the council to recycle. They would burn it anyway so I'm just cutting out the transport costs.
Any garlic that has sprouted in the fridge gets planted in a pot in the garden. It grows easily so I seldom have to buy garlic.
If I buy a jar of artichokes in oil, after I've used the artichokes, I use the artichoke-flavoured oil in risottos or salad dressings. Same with anchovy jar oil. Great for adding flavour to seafood risottos.
The white vinegar from the Christmas pickled onions goes into a spray bottle to dissolve any limescale build-up on shower tiles and taps.
Old Christmas cards are cut into tags before being put away for next year. I love taking care cutting carefully so it looks like a tag, not an old bit of Christmas card. Mundane creativity. 😊
Bar soap. The only soap I've found that is also a great shampoo is goat's milk soap. It cuts out all the plastic bottles. Try Cyril's Soap Shed.
I save jam jars and lids to use when making jam or bottling blackberries in the autumn. (You need storage space though - a box in the garage)