Pyrography!  It sounds a bit like pyromania, or pirate studies, but luckily its just a very constructive way of burning wood.  You use a small hand held tool rather like a soldering iron, with a heating element on the tip, to burn marks onto wood.  Various shaped tips are available to screw onto the element, the one I like best being a straight chisel end.  Just as in italic calligraphy, hold it turned at a roughly 45 degree angle and you have a lovely variety of line, beloved of scribes and old fashioned cartoonists like me.

Though when I say variety, there’s a lot of unpredictable variety, as the hot metal burns over differences in the wood surface, cools, re-heats and refuses to behave like a nice, clean pen nib.  Its the most awkward and uncooperative drawing instrument I’ve ever encountered!  But along with the random nature of re-cycled pieces of wood, thats all part of the uniqueness, every time…
It helps if you like the smell of wood smoke, as well.