well first you find the most massive object that you can throw and you should throw it in the direction opposite yourself. while you push the object away you would be exerting a force on the object for some period of time while you have contact with that object. In that entire time while the object is accelerating the astronaut (you) will be exerting an equal and opposite force on the hand of the astronaut and while the astronaut is pushing you would be push the opposite direction hopefully you would grab on to
well first you find the most massive object that you can throw and you should throw it in the direction opposite yourself. while you push the object away you would be exerting a force on the object for some period of time while you have contact with that object. In that entire time while the object is accelerating the astronaut (you) will be exerting an equal and opposite force on the hand of the astronaut and while the astronaut is pushing you would be push the opposite direction hopefully you would grab on to