The last few bits of art I've made were done with no sketch whatsoever, just made up as I went along. Mainly because I am squeezing them in between projects so they have to be quick but it's a nice feeling to just dig straight in and still end up with a final illustration despite zero prep work.
@AnimatedAF That's how I think some comic book artists like Ariel Olivetti and Stjepan Sejic work. An idea in their head, and just straight into coloring, no line art. Tho that is just my suspicion. That's the only way I can think of them meeting a deadline like in comics.