Here are three fragments of drawings. I’m starting on a larger project and it’s taken me a long time to figure out how to proceed. Here are some experiments.

This is my first attempt with Wacom tablet and Illustrator, neither of which I knew anything about how to use. I liked the variable line, but it’s too thick, so small details get lost.

Next I went back to my usual pen on paper. I like the details but it’s a dead line, which is fine for some things, but I wanted this one to look more elegant.

Bingo! A big thanks to Jeff Zugale, who told me that a line in Illustrator can be less than a pixel wide and explained how to make the kind of brush I wanted. Here’s the third version with a nicely varying yet thinner line, done on the Wacom tablet.