Some great sketchbook advice from Austin Kleon
...fill a page every day, even if it’s with grocery lists or scribbles or collages. At the end lf the year your sketchbook will be full.
Also: carry it everywhere, and instead of long at your phone or the computer when you’re bored, start making marks.
Also: remember that a sketchbook is a tool for thinking, a place to work your thoughts out on the page. It ain’t precious.