Buy in bulk and reuse the containers to avoid plastic.
Growin' yer own stuff is another good one.
Use simple soaps. I use plain homemade or Dr. Bronners stuff, or some locally made hippie soap. There is no reason a whole bunch of stuff other than saponified oils and essential oil for scent should be in soap. Really, trying to avoid synthetic things as much as possible is good, as most are traceable in some way back to petroleum, so just forming a lifestyle where you try your best to use things that are the product of biological reactions instead of artificial synthesis makes a huge difference. Biological syntheses are more likely to give the water used back to the planet, where a lot of industrial processes are really, really water hungry and use up a lot of water instead of borrowing it, as I like to say.
Going solar is also a good option. If you have a workshop or a a studio or something full of too many high power devices for solar power to work fully, you can still supplement your power supply with solar panels and a battery. Ideally, we shoulod all try to use less energy.
And composting organic waste! If you do the grow yer own thing, this is a must! Build a cistern and harvest rainwater too, that way you can have extra water for your garden that isn't pumped out of a well, lake or river.
And if you see an industry being wasteful, polluting or otherwise neglecting environmental responsibility, do your best to not support it, or try to reform or fight it needed and if you're able.