It’s good to have a few pencils handy next to your bed, next to the sofa, etc - (at least for me) drawing ideas occur to me when I’m least expecting them and its good just to be ready to draw at any point. I found out that a used bookstore near me sells used sketchbooks that are actually almost completely blank for $4 so check out your local used bookshops for deals there too. I draw more when I’m not worried about “wasting paper” in an expensive book.