I commonly use a neck roll draped on the neck to help support a child in improving his or her regulation.   Warming it up in a micowave increases its effectiveness in helping children to calm.  My daughter, when she was younger, would take a warmed neck roll to bed with her to help fall asleep. They are very simple to sew.

Cut a piece of fabric 24 inches by 8 inches.   Fold it in half with the fnished side of the fabric on the inside. Sew a seam on one end and the side, leaving one end open Use a pencil or ruler to turn the tube right side out Fill about 2/3 full of flax seeds (You can hold the end of the tube closed and check how it drapes on your neck before you finish it). Turn about 3/4" of the  fabric in at the end, sew a seam to close the tube.