There are so many things!
Instead of using rope or paracord made from petroleum, I collect my own natural fibers and turn them into cordage for most of my uses. It beats by far having to buy string at the store, and I can make it any length or diameter I want, two or three stranded or braided, etc. This is something I’ve done for a while.
I am also planning on repairing my outhouse door which rotted off, with a roundwood gate, using some wood from buckthorn and Norway maple and some dead juniper trees that I am already cutting down, rather than buying or using dimensional lumber which requires bigger trees. I always try to avoid things that require cutting down big trees—our forests need a lot of healing!
I’m also growing fungi this year, blewits and wine caps so as to make better use of the very woody character of the place where I live for the sake of feeding ourselves, and also intercepting local waste streams (sawdust) for food and soil building.
Saving jars and using them instead of tupperware.
A recent thread about making your own non-plastic tarps from duck canvas. I have made a lighter tarp by waxing a bedsheet.
https://permies.com/t/225610/toxic-tarp
Making my own glue from spoiled milk…
https://permies.com/t/369248/Natural-glue-finer-woodworking-lutherie
Relying on herbal medicines that work, as opposed to depending on synthetic pills and potions in plastic bottles. I’ve been saving many different kinds barks, cherry, honeysuckle, buckthorn, etc… I also gave someone catnip for a cold and it seemed to help a lot.
https://permies.com/t/370143/medicinal-herbs-recommend-beginners-start
Another thing—I’m cutting more Norway maple branches, both for sap, because they shade out all the other plants, and I also am hoping to grow some shiitakes on them!
I also have made swales and terraces in the past, which are excellent at intercepting and soaking water which would otherwise wash away soil and cause flooding, but instead go to feeding plants and restoring our water table. They also work in dry areas because they paradoxically increase drainage as well, and aerate the soil.
https://permies.com/t/366576/Capturing-precipitation