I think one of the most important habits is a habit of mind that involves never thinking you've found The Solution. I really don't think there is one. Different people will approach writing differently and will find success using different methods. The same person, at a different time, will find different tools effective. There are different markets, different styles, different goals and different definitions of success. So try everything, and keep trying everything. Don't be afraid to mix it up, and don't fall into the "it works for me" trap, not unless whatever it is that's working is still allowing you to improve (or if you've already met your ultimate goal and are satisfied to just coast). And have fun with it whenever possible.
I'll add to that one important thing every writer ought to do. Don't forget to read nonfiction. I can't tell you how many amazing ideas have come from the most unlikely of sources . . . real life. I'm currently listening to the audiobook edition of, The Royal Art of Poison: Filthy Palaces, Fatal Cosmetics, Deadly Medicine, and Murder Most Foul. I needed a hook for what was an otherwise unexceptional dining scene in my WIP, and found it while listening to the book. We humans are endlessly inventive when it comes to killing each other. Another thing I've taken to, is reading about the real life events that inspired their fictional counterparts. Melville's Moby-Dick wasn't created out of thin air, nor was Shelley's Frankenstein, or Stevenson's Treasure Island, or Doyle's Sherlock Holmes, or Wells' War of the Worlds. These great writers of fiction weren't writing pure fantasy, they were responding to events, new science, real people . . . and wondered, what if?
I agree that writing works best for each of us and we probably have to find the way ourselves. Personally: -I use music when I write(Without lyrics because they distract me. Mostly specific pieces depending on my WIP) -I write every day(It works best for me because by skipping a day or two, the tone of my story is gone and I may struggle with finding it) -I set writing goals(This is very important. They don't have to be many but they are daily and help me see my progress, like ''Complete 12A, or Finish Chapter10'') -Take breaks(Can't understand how some can write for 2 hours non-stop and I've felt envious of that but for me, my eyes may hurt after an hour or so. Sometimes, I take off my headphones for half a minute and look round my room, my mind empty, then resume) Also regarding writing in general, I haven't been doing it for long but it seems to me that if you keep doing it for a lot of time, it will organically grow and be better even if you don't use any advice. With consciously honing your work, this process happens faster. Regarding reading writing craft books, I suggest reading books depending on one's weaknesses. Emotion used to be painful to describe with active verbs and not just tell so I picked The Emotional Thesaurus: A Writer's Guide to Character Expression which was of vast avail.
