Plain Cahier (Moleskine Srl)
Ok, I know this isn't a book, but it's a notebook so technically allowed, right? I don't need to introduce Moleskine, but if you're not already in the cult then these are the notebooks used by Hemingway and Picasso. There are big notebooks, small ones, lined ones, hardback ones, all kinds... all of them the perfect size and paper for the task at hand. I use a variety and my brain lives in them, maybe there's something about putting down the phone and writing on paper which means I have different ideas? This set of pocket-size journals is my go-to: They're softcover so easy to throw into a bag or unobtrusively tuck into a pocket. And plain which is perfect for sketching a quick design, or making notes on the bus. The Cahier journal set is good value: You get 3, each 64 pages with the last 16 detachable. These particular one have red covers for a bit of extra character.
-- @genmon, April 2016.