I keep two notebooks consistently: my sketchbook and my daily notebook.
My sketchbook captures ephemeral content from my right brain: sketches, doodles, scribbles, random creative inspiration, and color combinations. This is the notebook I also take to meetings and workshops, where I can let my right brain run loose while the left brain pays attention.
My daily notebook stays with me all day to capture the mundane contents of my left brain before they leak out: lists of things to do and things I did, telephone messages, observations, dates, and deadlines. Sometimes I paste in receipts or ticket stubs or the label from something tasty that I’d like to try again.
I prefer a wirebound Canson Universal Sketch in 9″x12″ for the sketchbook and 6″x9″ for the daily notebook. On the outside, I personalize the covers with decorative paper, washi tape, rubber stamps, and stickers. On the inside, I make marks with whatever happens to be handy: pens, pencils, markers, spray ink, etc.
For a brief moment when my notebooks are new, they are crisp and clean and symmetrical. Soon enough, however, they become rumpled and bumpled with water wrinkles, their edges darkened by spilled coffee and ink over-spray, and their bellies fat with pasted-in ephemera and tabs made from washi tape — all of the things that make them MINE.