I also bought a Scribing Tool from Lowes, which is just a big hardware store if you don't have them in your area.
It looks basically like a pen, but the point is incredibly sharp and can be used to scratch pretty much anything. I used it to scratch lines into the top of this tower to make it look like a giant drone. I won't know how well it worked until I pain the sucker, but I'm optimistic.
|Tau Tower WIP - The pumpkins are not gonna stay there.|
|Hard to see, but the lines are scribed in right now.|