I've got a brush that does two lines at once and I very rarely use it. Most of the time that it's ever been used in the comic is drawing a spirally cord like on old phones or like this CB radio cable. It's a neat thing but very limited in its uses for me at least.
While drawing this I realized that I hate drawing vehicles. I wished that the world of ZR was even more batshit insane and I could just make up shapes and say "Yep, that's what they drive in this world..." but it's not so I have to do an actual semi truck sometimes. I've got an idea for a longform comic that I've been wanting to do about someone hunting down supernatural threats in a world where magic has shaped the course of history... in that comic I'm sure I'll be able to make crap up if I feel like I want to or go the complete opposite way and have like old timey cars in a quasi modern setting-- at least they'd be different enough to more likely be fun to draw.