While reading through The Natural Way to Draw
‘This is a memory drawing, to be done in scribbled gesture style, but instead of drawing a single figure or object you are to show the human being in relation to his environment.
Working in pencil, make a small drawing (about five by seven inches in size) of something you have seen during the past twenty-four hours. Put down as fast and easily as possible, and in any order, the various things you remember about a specific place and what was going on there. No more than fifteen minutes should be spent on one drawing. Make no corrections or alterations later, but go on to a new one the next day.’
pg 52.
This seems like an exercise that you could accomplish easily at the end of every day even if you have been very busy. I plan to label and date each of my drawings, and I bought a cheap pack of low quality photocopy paper on which to do these quick drawings.