My go to self massage tool is Yoga Tune Up Therapy Balls but you can release your feet and knee tension with everyday household items like a wash cloth. There really is nothing in the way of a quick self care session and this is one of many videos.
Tools recommended for all my classes: Yoga Tune Up Therapy Balls.
Size: Corgeous, Classic and Plus size balls
Order your balls:
https://www.eroticmovementarts.com/products