What are some rules you have for yourself working from home to maintain a healthy work environment?

I try really hard to keep my computer in my office and not move it around the house. For me its super important to have a physical cue when my day is starting and ending for work. That way I have a mental separation between non-work and work time.

Keep my workspace clean/organized, use lots of to do lists, go on dog walks or exercise during the day to make sure I take a break.