For many people on with ASD sitting still can be difficult. This is a major issues in school’s, and part of what makes life more difficult for those of us on the Spectrum. An effective tool to help focus is the utilization of a fidget, also known as stim toys. There are a variety available, each providing a different fine motor action to help focus the mind. A great site I’ve found to buy stim toys is Stimtastic.
Some of the options available include Pencil Top Fidgets,
Or Stim Jewelry such as Spinner Rings.