There's this weird sentiment going around some circles that there are no rules to what makes a good novel. When Hugh Howey or Andy Weir or whatever can come out of (relative) nowhere and make all of the money, what's to stop you from doing it. Right? So, we come across this weird strata of writers who shrug their shoulders at a lack of success, and they don't engage in self-examination.
Even the 10,000 Hours theory, which there are arguments for and against, points out that the 10,000 hours you spend are worthless if you aren't examining what you're doing with a critical eye. Without that, it would be like driving your car and running into a fire hydrant every day, thinking that running into a fire hydrant was how you drove a car. Not a bug, but a feature! You'd be wrong, and people would think you were insane.
Stop Talking about It
So, apparently something like 80% of Americans want to be writers. Sure, it seems sexy and amazing. Everyone wants to be a writer, or at least wants to write a book. The number of times I've sat next to someone who goes off talking about the brilliant idea they have for a book that they're going to write has already gone beyond me caring to count it. I've got better things to do!
Turns out there's psychology behind it. Most people, when they tell their friends (or whoever they can grab) "I want to write a book about flying donkey's delivering pizza through space" their friends say something between from "oh my god that's the best thing ever and you're beautiful" and "cool". Then inside the wannabe writer's brain there's a flood of happy chemicals. Its the ones you get flooded with for actually writing the thing you said you were going to. So, you can't get rewarded the same way anymore. Then you just keep going around talking about writing that thing, and never doing it.
Meanwhile, someone else writes a "Murphy the Donkey and the Pizza Escapades" and gets it published and gets a movie deal. Then you complain that you had the idea first, and isn't it unfair.
Finding Friends that Blow Smoke
This is one of the best things I've found. Ever. A group of people who don't blow smoke. I have a group of close colleagues and friends I talk to about ideas, I get to read things, etc. Membership to the group requires you to not blow smoke. If I send something and I get no criticism, I assume I'm being lied to. If you're lying to me about my writing, then I'm doing a disservice to myself by sending it to you.
Too many writer's groups sit around full of people telling each other how great their writing is and the tragedy it is that people don't appreciate their genius. Or their skill at writing. Or whatever.
This one just makes no sense to me. If you aren't famous from you're writing, if you aren't able to sell it or whatever, you're doing something wrong. Finding people who tell you "no, you're doing everything right" isn't helpful. No one who's successful does everything right. If you're going to be successful, you have to be screwing up.
Deciding if Someone Else Did it, You can Too
This is a weird one, and a complicated one, but it just pisses me off. I've talked to a few writers and pointed out problems in their writing, like continuity or their magic system not making sense. Then they get in a huff and say something along the lines of "Well, J.K. Rowling's magic system didn't really make sense either" and that will be the end of the conversation.
They're right - the Harry Potter magic system doesn't really make any sense at all. But that doesn't matter. That's like pointing out that a referee missed a call somewhere else in the game, and determining from that that it isn't against the rules, or that the audience won't hold it against you. Harry Potter presented a premise in the first book - magic is going to be fast and loose, and the story is more important. In exchange for that premise that is also a promise, Rowling doesn't Deus Ex Machina things. Instead, problems are invariably solved more by learning a lesson, being clever, and applying what they've learned previously in the book.
One of the biggest things you need to do if you're going to make it as a writer is learn the rules. It is just like driving a car - most passengers aren't going to care if you speed a little, or maybe only do a rolling stop at the stop sign, but only if they think you can actually drive. You know the rules before you set out onto the road, and it is voluntarily and with knowledge that you depart from them.