STRAW!! The main thing I do in the winter, is switch to straw bedding. It keeps the coop a lot warmer than regular shavings. It’s also fun to scratch around on. (For the chickens that is). I also suggest using droppings boards under the roosts during the winter, to keep the coop cleaner, and more comfortable to live in.
I choose not to use artificial light in my chicken coops for egg production for a couple of reasons.
Last year I used rubber livestock feeding dishes for water and they worked a lot better than plastic ones. I’m looking at heated waterers the year, to see if they would be worth it. The rubber is nice though since you can bend it to get the ice out.
This is year I’m wrapping my runs in plastic (tarps) to keep the snow out. I’ll also put straw in the run.
Hope this helps. I’m sure I’ll think of more stuff.