There was an interesting article (interesting to writers, anyway) in Friday's Wall Street Journal called How To Write A Great Novel. It's not a true How-To so much as a Here's-How-Others-Have-Done-It.
While I've never written in the bathroom or gotten dressed up as one of my characters, over the years I've found methods that work for me. They're not the same methods that work for others. I know one author who writes all her books while sitting in her bed with her laptop on a foam lap desk. She gets lots of work done this way, but if I tried it, I'd fall asleep. On the other hand, I frequently manage to hammer out sticky plot points while gardening, but a lot of writers I know consider weeding a hellish activity.
The thing is, you only know what works for you by trying different methods, and you can't do that without actually WRITING, which is hard work. Read the article and you'll see what I mean. The gist of the piece is:
1) No one process works for everyone; the writing process is as individual as the author
2) Writing is hard work
3) Writers--yes, even the best--must be willing to revise to be successful, sometimes throwing away big chunks of their hard work in the process
All three are good lessons for any writer.