The high price of (many) new zines today is why I love zine libraries, and libraries with zine collections. Also while I prefer paper zines, I do appreciate that so many zinesters are putting digital copies online for free!
I wonder if many new zinesters are coming into the scene from an Etsy business perspective, where you have "production costs," and not a punk DIY perspective, where scamming free copies from Kinko's and re-using postage stamps was a common way to save money. That might explain some of the prices...
Buying secondhand over new. I love thrifting so that's a bonus for me! Also using what I have, repairing what I can, or just going without something versus buying something in the first place.
Eating less meat, and prioritizing locally grown veg when possible.
Taking public transit, walking, or biking everywhere. If going long distance, I try to take ground transportation (trains, buses) over flying.
Reducing energy use eg turning off lights when I'm not in the room. You'd be surprised how many people still don't do that, haha!