Generally, I use a pencil. This is probably because a pencil is what I use most often. It’s easy to fix mistakes and you can start off sketchy and darken the lines later to make it look a little better. Themes come from whatever I’m feeling at the time sometimes, honestly, it’s random. Often, I’d like to sketch a scene from a story, but it’s difficult. I’m not very good at planning ahead, and sometimes will change small bits of the drawing partway through. I’ll often ask others for their opinions as well.
My current work tends to be pencil drawings of characters from my stories. I really need to work on poses rather than just doing shoulders and up all the time. In the future I would also like to broaden what I draw with, so it’s not just pencil all of the time.