All self-help books in one single line
That’s it. Self-help books should just say this 50000 times over 300 pages. Instead, they tell you stories and anecdotes about people who did exactly that and things went well for them. They tell you shitty mnemonics and 7 steps and 50 goals and all the rest of it. But that quote is all you need to understand how to make it in life.
So if you want to become a better X, don’t dream that you’ll be a better X. Train for it. Over and over again, for however long it is going to take. Some things, like keeping yourself clean, are easy. Others, like getting along with people who aren’t clean, for example, are harder. It only gets better with practice.
Every sportsperson knows this. You want to get better at basketball, you have to train for it. And the better your peers, the faster you grow. This applies to other places too: research, forming and keeping relationships, following diets, and the list goes on.
There, I just saved you a whole lot of money on buying self-help books, and time on reading them. Now spend all that time and money you saved on training!