There are many great, free online resources available from reputable mental health organizations such as the Canadian Mental Health Association, the Mental Health Commission of Canada and the Canadian Alliance on Mental Illness and Mental Health. Something as easy as printing out a poster or pamphlet that is readily available online is a great and simple reminder to staff members to take care of themselves and make their own health a priority.
Recently, a school jurisdiction shared with me the idea of a health board in their staffroom, where staff members post positive messages about other staff or things that they are grateful for. As a result, they noticed that this board has become a focal-point in the staffroom and has encouraged conversation and built positive social relations among staff.
Another idea is to take a short break to unwind and refocus. I have heard of many school jurisdictions setting time on their staff meeting agendas for healthy break activities.