uhhh i draw a lot of fan art so usually i just draw what i want to see the characters doing or what i think would be a cool pose.
i also draw when I'm out and about so whenever something catches my interest or just looks really nice, i try to replicate it or at least capture the essence of it in my sketchbook.
my original stuff, rare as it is, sometimes ends up being things that I'm trying to sort out within myself. one of my more recent characters was entirely based on how i was feeling after a certain thing happened. i've also been writing and drawing designs for a comic i'd like to make one day, and it's essentially just my way of working through my thoughts and feelings.
most of the time though my original stuff is "hey you know what would look cool? if i drew a character with this hairstyle/outfit/look/pose" haha