A couple of matters have been mentioned that again point up the importance of systems knowledge. Some aircraft have impulse couplings fitted to both magnetos. Some have an impulse coupling fitted to just one. Some have no impulse couplings and have retard breakers instead. Some have starter ‘vibrators’. Some have electronic ignition systems. Some need to be primed by an electric pump. Some have 12volt batteries, some 24.
Without knowing these things and their implications, efforts to swing or jump start an aircraft engine may at best just result in bigger biceps and, at worst, death. Major engine or airframe damage is somewhere in between.
The place to learn these things is in the comfort of your lounge chair with a cup of coffee before the big trip, not as the sun is setting over you and your aircraft in the middle of nowhere. It may be that you resolve never to try to swing or jump start the aircraft, either because it will be futile or entail risks you are not prepared to take. But make that decision on an informed basis while not under pressure. And have a ‘Plan B’ for the (fortunately unlikely) event of being stuck in the middle of nowhere.