JK Rowling's video series On Writing was helpful for me, because she basically doesn't make any recommendations and just talks about her own process. At one point, she says explicitly that nobody can tell you how to write.
What struck me most was her attitude towards writing. A lot of people with that amount of money and fame would rest on their laurels, but she just wants to make good stories that people enjoy reading. It's like writing is part of her being. It made me realize I either have to quit writing or I have to be that, because anything in between is a waste of time.