I expanded my understanding of throwing a hook in Boxing, prior to that I did a kind of looping overhand that I learned as furi-uchi, it'sa good punch but longer range and with different mechanics than the lead hook uses, more like the longer range Muay Thai hook i've seen.
First, I find that training the lead hook is just generally tough. I am working on mine and it is slowly improving, but I've run into a conundrum:
I think in practice that the mechanics of the typical vertical Boxing hook bunch are maybe not so good outside of Boxing. If you throw it really "classically" you will hit with the actual knuckles, but once you start working on a moving target, you end up often "slapping" with the inside of the hand, and the perfect form classical version hits less often. This is maybe less of a problem if you throw a "european" hook with the palm down, but the same problem exists the second a person moves their head.
You can watch lots of boxers and see this. If you're wearing gloves this is still pretty effective, in fact I've had it inadvertently turn into a kind of rabbit punch and wobble me pretty good once, so I know it "works" in a boxing context. The problem is, without wraps and gloves you will absolutely demolish your hand hitting anything very hard with this. I actually know someone who was a boxer, got into an altercation, ended up "hooking" an attackers head like this multiple times in a self-defense situation, and ended up with pins in both arms for half a year or something due to the injury. I imagine that's an extreme example, and to the techniques credit my friend survived and repelled the attacker.
So, in a practical sense I am wondering if one is better off just training a shuto or outside-inside hammerfist, which is a similar motion to the "slapping" hook without hitting with the most vulnerable part of the hand.
The combination of these things makes me thing I need to seek out a more practical hook punch, and I am curious what other people's default hook punch is, if anything.