Some of these are embarrassing/will seem ridiculous but all is fair in love and minimalism!
-Keep house at 18 degrees (64.4F) year round
-Keep lights off as much as possible. Tv lights the living room (lol)
-If there are lighting fixtures that hold multiple bulbs, only use 1
-Anything and everything is done on the lowest setting if possible
-Device need charging? Gonna be at work later? Charge it there.
-(Get ready to laugh) Pee outside (backyard). Why waste water?
-Hiking shoes breaking? Duct tape bitch! No one is there anyway.
-Summer? AC? Nah! Cool house at night (open windows and have fans running) then shut blinds/close windows when sun starts rising. If house gets a fair bit of shade you can stay comfortable most of the day. Run fans, even one from basement pointing up the stairs to bring cooler basement air up.
-Like video games? Me too, a lot. Online rental sites and sales. Hardly ever buy new (last new game purchase was March 2017).
-Cable tv? Been like 6 years. Internet and Netflix does the job.
-Dish soap or liquid hand soap getting low? Add water, shake and presto! Full bottle again. Also works with cologne, shampoo, conditioner, eye glass cleaner, etc. Sure it's a bit degraded (not the right word but I am blanking at the moment) but it definitely extends your usage.
-Some jurisdictions have varying hydro prices. Find out if your area is one of them and if so try to do laundry, dishes, etc in those hours. Timers help with this if you're at work.
-Do you get a drink, finish drink, throw cup in sink then get a new cup for next drink? Silly goose, quick rinse then re-use! Also works for bowls and dishes and silverware.
-Treating yourself with some takeout? Cool, do that once every month or so myself. Get the big size (full dinner vs. half, for example) then set some aside for another meal. Two meals for a bit higher of a cost works out better than the slightly less expensive one that lasts one meal.
-Unless it's one of those scorching "fuck my life" days, if you're driving out in the summer windows down uses less energy than air conditioning. And if I do run the AC (or heat in winter- bundle up right though and u can avoid this) it's as low a setting as possible.
-Bring my lunch to work (well breakfast lunch and dinner all in one as I do intermittent fasting/one meal a day and work 12 hour shifts during which my eating window falls) and when I am done there is Tupperware to wash? Wash it at work, why waste water at home?
-Take vitamins or other supplements? I take the proper dose most of the time but every so often (once or twice a week) I'll either skip them or take a reduced dosage. Stretches them out more over the course of a year.
-Holes in clothes? Mend 'em. Wash clothes less often so they last longer.
-Run washing machine on cold water setting.
-If you use disposable razors/razor blades, once you are done shaving get the hair out, dry the blades perfectly then run them several times across your forearm(s) in the opposite direction that you would run them to actually shave (hope that makes sense). Do like 10-20 "backwards strokes" and this resets the alignment of the blades which gives you a few extra shaves with the same blade.
-If you use teeth whitening strips and you don't have giant ass horse teeth you can cut the strips in half and get double the use out of a box (you can also use them a lot longer than the recommended thirty minutes but TEST THIS CAREFULLY at first please. You may get tooth sensitivity (I do not and have worn them for upwards of four hours at a time). Please don't tell Crest et al this as I don't want them making them smaller to stop me from doing this ;)
-If you cook bacon you can save the grease and use it for cooking (saves you from using olive oil or whatever and it tastes awesome!).
-Sometimes you'll think you need a new pair of shoes when really all they need is a cleaning and maybe a polishing. If they aren't ripped to shit but just dull, try that first.
-Drive my car conservatively and keep up with maintenance. Use same car forever (I drive a 2003 that still runs great).
I'm sure there's more but that's all that comes to mind at the moment.