Seriously. I've never seen anyone who is simultaneously this fluent in applied mathematics while having this level of visual sensibility as an illustrator. Truly a polymath.

It is a magic you can learn :)

Seriously, start experimenting, you'd be surprised.

However, overall experience with math and various mathematical experiences help so much, as well as some kind of artistic experience -- even just talking to artists, seeing a few videos on theory of artistic composition, etc. I highly recommend going down this path.