I love your idea for the intro and the outline has a logical flow.
I understand you don’t want to create too much hype with your subheads, but I feel the current subheads are perhaps a little harsh and factual. The lack a sensory touch, a little subtle.
What about something about “How to let your mind wander back” instead of “Routine for inspiration”?
Or instead of “clarity through structure” consider a referring to a pattern that you’ve found by organizing your pictures, e.g. you might have found a series of images that remind you of lavender, so you call this section “The scent of lavender”. This feels a little more poetic.
These are just suggestions to consider. You have to following your own gut feeling about what’s right for Sarah and how you want your voice to sound.
Enchant readers. Woo customers. Win business.