I just noticed this new tag and thread. I have a special person in my life who I want to make a special book for. She very much likes biking, as well as the nature and outdoors. One of my ideas to make this book special is to make little sketches of all the things she likes, and then photocopy them onto paper to use as the pages of the book (I can't use the pencil originals in the book as the graphite will rub). As a result this isn't in tune with your prompt, but it's my daily sketch for the day. Thank you for understanding.
All sketches are welcome :) I really just put an idea because I know it can be tricky to come up with one everyday. It's funny because I was thinking of the whole " draw a bicycle without looking at one" thing so you read my mind. Good luck with your book it sounds awesome and meaningful !