I don't know how. I'm certainly not one, and I don't know any, either. I suppose you need to be born with some superhuman ability. Maybe if you could fly or breathe under water you would be a good candidate. Obviously, if you are invincible you should be able to sign up for a superhero gig. Otherwise, I've got nothing.
I once knew someone who could burp their ABC's. I don't think that actually qualifies as superhuman anything. But the ability to burp on demand may have some possible health benefits.
Then there are those people who can contort themselves into unnatural shapes. That one could be borderline superhuman, but I have a hard time envisioning a scenario where some dude, or gal, twists up like a pretzel and rescues an Alpine village from an avalanche. Maybe if Earth was to be invaded by aliens that were afraid of pretzels … Like I say, it's difficult to see that one going anywhere.
Quite possibly the closest we mortals will ever come to being superheroes is by just faithfully doing the daily things we need to do. Maybe true superheroes are those people who manage to suspend their self-interest as they give their life away to help others who are in need. Maybe Mother Teresa's habit was really a cape in disguise. What if what we saw of her in public was just the tip of the iceberg?
Mayhap this is some random pointless ramble. Then again, it could be a surreptitious way of introducing the concept of the series of books that will follow the Falcon series.
Wrath of the Falcon is scheduled to be released in June of 2016. I guess there's still plenty of time to speculate on what might be officially announced next.