The three biggest problems with learning how to fight with your fists are:
1. Most methods do not teach touching and slapping drills before punching.
2. Various martial arts styles tend to use only one type of knuckle targeting.
3. Most [boxing/MMA] coaches who teach mechanically optimal punching do not understand the mechanics of the bare knuckle situation.
The best thing you can do for yourself, if you are starting out, is to practice pressing your fist against various surfaces and developing wrist strength and a tactile appreciation for injury points through this isometric activity while at the same time practicing touch and slap drills on a bag. Your punching should be learned in the air, shadow boxing is the first place where you should clench fists, not against the bag. You will miss more punches in sparring and fighting in sport setting than you throw, so learn how to miss without hurting yourself first, by hitting air and not hyper extending your elbow or clinching your fist too tightly until the instant of impact.
Being a Bad Man in a Worse World
Fighting Smart: Boxing, Agonistics & Survival
These are some the best defense videos I've seen. It's amazing how much talent is strown about this country that no one ever hears of. This is not just in this one area but in science and all kinds of fields.
At the risk of being a spoil sport, yes I do that sometimes. I see for myself, an older out of shape guy, I had a mental flash after watching these seeing how many things could go wrong it appears to me that the best thing to do would be to carry a can of the most kick ass pepper spray that you could afford. It's not kryptonite but fairly close. I've seen what it did to Trump supporters.
I can see how these videos are invaluable. If you were forced into a situation even a little bit of training could make a huge difference against a much larger person with no training.
@ Sam:
This very instructive video was hosted on this site not long ago. No incredible power needed and faster and less telegraphed than a punch.
youtube.com/watch?v=y-VP12g49TI