Does anyone have willpower 'mind-hacks' they're willing to share? I find the hardest thing is to just get started, after that everything's easy.
As far as willpower, try studying a martial art. I studied for 10 years, and taught for 6 of those. Best case, you want a martial art that is both a contact art, and also does the "meditation" side of things.
Aside from regular exercise, a good martial art will teach you a lot of mental conditioning. Meditation for stress relief, breathing regularly while on an adrenaline high, ignoring pain, and thinking your way out of a stressful situation, rather than letting the reptilian part of your brain take over.
That being said, you give solid advice. Studying a martial art definitely gives you more willpower.
Imagine one smaller person, and one larger person. How much more skill does the smaller person need to defeat the larger person, in a striking art? How much more skill does the smaller person need in wrestling? In general, wrestling and ground have a more expensive exchange rate, because size and strength are larger factors.
You can defeat larger people, you'll just need to be more skilled.
Better might be: available reserves of neurotransmitters.