According to Nazeer and others, the repetitive behaviors we see some Autistic people doing, flipping their fingers in front of their faces, flapping their hands or rocking back and forth may be one way of coping with a confusing storm of sensory information. They focus on their fingers moving, or the pattern of their rocking and it helps them to put everything else in the background.
One method is to draw attention to what needs focus, for example, watching where you are walking or running, so you don’t run into tables and doors.
A second that has been reported to help is to get the person to do less obvious, more usual type of repetitive behavior, for example, tapping their fingers lightly on a desk, or having a stress ball (one of those squishy balls) that he can squeeze, or putting his hand in his coat pocket and turning a paper clip over and over instead of doing it while holding the paper clip in front of his face.
Related to sensory integration, a fourth “method” is to change the environment