In writing circles there tend to be many sets of rules about how to do it "right." For example, you must write every day. You must ignore the sparkly new idea. You must insist on a certain word count per day. You must outline (or in some cases, you must not outline.) Sometimes it reminds me of when my husband was in medical school. Before exams, all the students would be gathered in the hall comparing notes on what they were supposed to have studied and what would be on the test and what the right answers were. They would work themselves and each other into a frenzy of fear and worry and panic. Sometimes writing communities are incredibly supportive. And sometimes they have that med school panic flavor.
I have come to a new conclusion. There's really only one rule that counts: Do what works for you. And if that changes from week to week, that's fine. If butt-in-chair is working, go for it. If the next week, you find that butt-in-chair leads to days of Internet surfing or ceiling staring, maybe it's time to go seek inspiration. If outlines work for you, use them. If you're stuck and can't figure out where your outline needs to go, try writing the scene that would come next out long hand. See where it takes you.
Writing isn't a science. It's an art and a craft. And some elements of crafting requiring precision and discipline. Some elements of art require the opposite -- freedom from the need to be precise or disciplined. So what's needed may change in different phases of the writing project or in different phases of your own personal state of mind.
My advice is this: Go with it. Trust that your intuitive self knows what will work for you and let it be your guide.