Creativity is a habit, and the best creativity is the result of good work habits.
Twyla Tharp composed a popular book on creativity, The Creative Habit. It's a wonderful book that I recommend at a certain point during my Foundation Course in Drawing and Watercolor and also to some creative coaching clients.
One thing, though. From my experience, if creativity is a habit, it's formed by practice. You don't establish any habit right away. You have to practice creating a habit, let's say drawing and watercolor until you rewire your neural pathways so that what you're practicing becomes a habit.
However, my experience is that with any creative practice, you are involved, to a large degree, in discovery. You have to be able to continually tweak what you're practicing, sometimes on a daily basis, in order to expand your abilities and understanding.
In other words, if you establish a particular way (habit) of doing a drawing or watercolor and then discover that you have to change that particular way in order to grow as an artist, you have to un-learn certain habits.
As a different sort of example, let's say you've learned a Mozart piano sonata so thoroughly that it's ingrained in your neural pathways and muscle memory and you can play it "by heart". Then you discover that some of the ornamentation and a couple of notes you've learned are wrong and you have to un-learn and re-learn those parts. That's difficult and requires more practice to change what's become habitual.
Actually, I think that habits in creative work mostly consist of establishing the habit of sitting down to practice. Also, sometimes, establishing parameters like, I will sit down at 4 PM for 30 minutes to practice drawing. So, I don't think that creativity is a habit but the habit of practicing creative work is crucial to creativity.
Seth Godin has been blogging daily for... gosh, I don't know how many years now. His posts are usually short and sweet but highly inspirational and effective. He committed to the habit of writing daily posts and continues to practice daily (for all of our benefit).
Anyone who meditates daily knows that there is the habit of sitting down to meditate and then the practice of actual meditation which can be (and usually is) wildly different during every sitting.
Setting parameters helps with establishing habits that you can practice within. Particular methods designed to lead you step by step through progressive exercises are also extremely helpful. Commitment is vital. Finally, there's nothing like accountability to keep you honest and on track as you establish your habit of practice.
Practice rules. Habit helps.