Sharpies and colored pencils
Where'd you go Bernadette was a great book, I downloaded the free e-book, and also listened to some of the audio book on YouTube.
Although the book itself, was great, YouTube would not be my first choice for another audiobook. Unless you use a "youTube to mp3 converter" and an mp3 player, I wouldn't recommend listening to audiobooks through youtube on your phone. With this recording being (I think) 9 hours, it obviously took multiple sittings - not only did I have a hard time finding my spot when I went back, but if I missed something, and had to rewind, it was a nightmare. Also, I had to keep my screen on the whole time, because the phone thought I was trying to "watch something" and would stop playing when I touched the screen or turned it off.
I was having some trouble with finding art inspiration, and this book helped me come up with this "version" of the cover. I had a lot of fun with this drawing.