This is the most important topic in Aging Well!
-Grab bars. Lots of them.
-Handrails on both side of the stairs.
-Rugs attached to the floor, no loose edges.
-From bed to the bathroom: emergency support all the way.
-Carry things reasonably, don't overload your arms with all you can carry at once.
-Kitchen: things on shelves not too high or too low.
-Simple exercises to improve balance, leg and core strength.
-Good shoes, cleats for icy weather.
-Have a nice walking stick or staff for outdoor walking.
(I recently had a serious bout of vertigo, and all of these were very important for my safe functioning.)