I also save all the elastic bands from bunches of spring onions Me too.
I don't throw a bowl of soapy washing-up water away until I have cleaned everything I can think of with it, like the patio door frames, trainers, empty plant pots etc, the floor by the cat's bowl, whatever. In hot dry weather it is used to water the grass.
We cut up old envelopes and save the paper for shopping lists.
We have proper dishcloths that last forever and are just bunged in with the next wash.
We don't always flush the loo if it is just a wee
I cut up old plastic bottles and use them as mini greenhouses to protect seeds and cuttings.
DH is often delivering round and about village lanes so he keeps an eye out for roadside stalls with local veg, free range eggs, home-made jam and stuff like that. We also buy sacks of potatoes in the winter for about £12 - we keep it in the shed and one sack lasts for a couple of months. I am agog at the price of spuds in the supermarket.
Home-made sloe gin beats any of the fancy pink stuff they sell.
There's chives, rosemary, mint and marjoram running riot in the garden, so we have free fresh herbs. Buy one garlic bulb, split it up and plant the individual cloves around your rose bushes and tomatoes - the smell keeps the greenfly off and you get a new crop of garlic into the bargain.
We don't have food waste if we can help it, and when we make casseroles etc then we make a bigger one and freeze the extra in those plastic boxes you get with a chinese takeaway.
I have been known to use cut-up bits of cornflake packets and layers of gaffer tape to repeatedly mend holes in the soles of my favourite boots.