I love coffee shops because 1) I get out of the house 2) I don't like coffee too much but I do love the blended drinks and 3)Studying characters from life is more fun than looking at photos.
I have pages and pages of these doodles. Sketchbooks are so important because it is where you can have fun and experiment. No one is judging you, its just you, your pen and a blank piece of paper which can be daunting in itself. One thing I tell my students is just draw, don't treat these sketches as something ultra precious and that you have to put on a show for someone to look at. By doing that you are already limiting yourself to what you can do, adding even more pressure to the art of sketching.
I love looking at other people's sketchbooks because it is such an honest look into their art, no frills just a lot of imagination and exploration. A lot of times you just see finished work that has been polished off in post or edited to take out all the bad sketches which is a shame. Everyone has bad sketching days, even the big boys. So here are some pages straight out of my sketchbook with no alterations.