1.Guard your face. If the attacker is trying to punch you or grab you from the front, put your hands on your forehead in a "Not in the face!" sort of gesture and your arms tight on your body.
2.Stand with a wide base. Both left-to-right and back-to-front, keep your feet diagonal from each other in a kind of martial-arts stance.This will lessen your likelihood of getting knocked or pushed over.
3.Assess your assailant. Look at their hands. If they were about to attack with their hands, they would have their hands out.