I can’t imagine not drawing. I draw because I love to draw. It helps me observe and process visual ideas. About 50% of what I draw is pure fantasy, the other 50% is drawn from observation or from memory. What goes into my sketchbook is not overly planned. The results are often surprising to me, actually.
This shows the type of sketchbook I have used for many years. The format is slightly bigger than my hand, and it travels with me everywhere.
The pen I use is called a sharpie superfine. Thank God those were invented. I buy them by the dozen. A sharpie doesn’t fade and it is waterproof, so I don’t need to worry that the ink drawings will run together if the pages get a little water on them.