On one of my writer's lists, people are discussing good writing habits, and I'm afraid that I seem to have few of them. I can't write while music is playing. I don't keep a stack of post-it notes nearby with bits of info, draw flow charts, interview my characters, write an outline, do copious amounts of research, etc.
As with any creative process, I think that whatever works is the right way. If you can listen to Metallica while you're typing away - do it. If it inspires you, even better. If you believe in muses and set out offerings to yours, do it. (But don't expect me to kept a straight face while you tell me about it). If you write historical fiction then you better do your homework, or prepare to be mocked.
Most of my non-typing writing work is done in the car as I sit in traffic. I think about the story arc, I puzzle out sequences, I imagine scenes. However, if I come up with some really great turn of phrase while I'm mulling a story, I don't lunge for a pen and the back of an envelope, because no matter how great it sounds in my head, I know that on the page it will come of as too twee (to borrow a lovely English expression). Besides, once I have this incredibly great phrase, I have to find a way to work it into my scene, which usually means some heavy-handed manipulation of dialog. So then I have all this clunky mess working up to one great phrase that only I adore. To avoid that, I murder that darling before it hits the page. All I try to remember is the emotional impact of the scene. That's what the reader is going to take away. If they notice the writing, then I'm trying too hard.
My research methods would shock most people. I shouldn't even admit to it here. What I do is get lucky after the fact. It's terrible to rely on it, but it seems to work for me. For example - in one story, I based my civilization loosely on the Inca Empire. A small plot point was that everyone in the civilization owed the government physical labor as part of their taxes. If you served in the military, you were exempt for life. Otherwise, one month a year you were out paving roads or building city walls. After I wrote that, I was researching the Inca religion and found out that the Incas had a system called mita that was a tax every citizen paid the government in the form of labor. Do I live a charmed life or what? Similarly, when I was writing Chaos Magic (as Jay Lygon), I had this concept of godhood as simply another state of being. In my fantasy world, gods weren't immortal. Then I was reading one of my Buddhists texts, and it showed a wheel with the various states of being. Human was one, hungry ghost another, and insect, and... God. And since these are stages of being on a karmic cycle, that means that gods aren't immortal. Aha! I won't even go into how well Wiccan beliefs dovetailed with what I'd already envisioned. Now, if I were trying to write a historical - even alternate timeline, or setting it somewhere I didn't know, I'd research everything down to the cracks in the sidewalks before I wrote word one. With fantasy, I don't have to, but I always feel better when I can find a real life example of what I envision. After all, even in fantasy worlds, the laws of physics apply.