I have made two different varieties - one for the sole of your slipper, to wear while sitting (it is a little uncomfortable to walk on the inserts and raw rice) and the other to lay on the top of your toes (which you can wear while walking around).
Additionally - similar inserts could be made to insert into your mittens. Just had another idea - the inserts could be slipped inside your boots too!
Step 1: Materials Needed
Raw rice or whole buckwheat seeds or buckwheat groats (do not us buckwheat hulls)
Step 2: Creating Your Inserts
Similarly, trace the top of your foot on a piece of paper. Cut two tops from the pattern - again flipping the pattern over so you are creating a right and left top.
Step 3: Cutting and Sewing Inserts
Pin and straight stitch 1/4 " around, leaving a 1" opening. It would be a good idea to stitch again just to be sure the seams are secure and rice grains aren't able to escape in the future.
Turn all inserts right side out.
Step 4: Filling Your Inserts
Stitch opening closed - again, consider stitching twice.