Body speed is a great way to create more spin when chipping and pitching. With the club traveling on a shallow path, the body can accelerate through impact. This increases the speed the club head moves past the ball. The faster the club moves past the ball, the higher the spin rate off the club face. This increase in speed and spin will result in greater receptiveness when your ball lands on the green. If you are looking for your shot to roll out more you can slow the speed of your body to reduce spin off the clubface.
Another way to create more spin when chipping and pitching is through your angle of attack, you can learn how to do that here.