The act of filling a sketchbook is the act of becoming comfortable transferring your thoughts from your mind onto a page.
As your sketchbook fills up it will become as unique as you yourself are. Every artist will use a sketchbook in their own way, but when you become very comfortable in transferring your thoughts onto a page flipping through your sketchbook or notebook will look like a peek into your mind. I try hard not to be precious about my sketchbooks. I don’t expect my sketchbooks to be beautiful pieces of art; I expect them to catch ideas as they fall out of my brain.