Something I've learned is that writers who give advice on writing are giving advice on how to write like them under their circumstances. Anne LaMott, for example, gives excellent advice on how to be a writer if your father was a writer, if you have a pet agent you can subject to your prose for ten solid years before producing anything noteworthy, and if you don't need the income generated by mass-market appeal. Stephen King gives great advice on how to write mass-market fiction quickly. John Gardner can tell you exactly how to be an esoteric high-brow literature professor with limited output.
My editor turned me onto Stein on Writing, which is the advice of an editor on what sells. It's brutal and not even vaguely encouraging - it is the windshield LaMott's bird flies into. But having written screenplays for ten years I was mystified by how non-commercial and loosy-goosy all the advice these "writing gurus" were giving. Then I read Stein and I was "a ha. It's because they wrote these things after they were famous and could get their grocery lists published."
Yes. I was going to come back to this post to say that it can be very enjoyable to read how famous writers think you should write, but if you want to draw meaning from it, you have to follow the advice that is going to help you write in the style and method you want to write.
It is just about defining your own voice. You can't possibly take everyone's advice if you want to have a distinct voice or even say very much at all. But the same can be said of style advice, home decor advice, art advice - hell, Hemingway is often quoted for saying "Write drunk, edit sober." I have never, ever been able to write drunk. Once I'm past tipsy, my attention for writing is completely shot. But clearly it works for some people.
If Stephen King didn't write for 8 hours every day the man would probably go nuts with the boredom of having no job/driving purpose. Admit it: we all need things that force us to go. That can be work, things in addition to work, things utterly outside of work, whatever. But if you have a full time job and/or kids and/or another job and/or whatever, writing an hour a day might not be possible for you. It might not be enjoyable. It might just kill everything you like about writing.
Read it all cuz it's interesting, take to heart what resonates with you.