I take mine almost everywhere these days which allows me to sketch at my university office, in coffee shops, and the like. And of course I can always step outside the studio to capture some of the local color. The small watercolor sketches posted were all done in 2016 in one of my pocket sketchbooks. The ones I like best measure about 3x5 and are made by Moleskine.
These are a few pages from one of my sketchbooks. All of these date from last year. All of these were sketched in pencil and then painted. Hard lines were finished with ink but sometimes I used watercolor pencil.
The two-page image to the right is about a year old, showing a red amaryllis in full flower. Although it doesn't show in the painting, there was perhaps six or seven inches of snow on the ground, and it was quite cold. The bright blooms cheered me up.
Sketching on the spot hasn't been my forte, but with the ease use and improved portability, anybody can do outdoor sketching.