Usually I see something really cool and make an off-brand version of it lmao.

Sometimes I just have like a certain theme or archetype I want to fill and decide to make something to fit into the gap. Nil was made because I wanted a small, sassy imp creature with a mean streak. Mari was because I wanted a cute, bubbly deer girl. Mizuki was because I wanted a boobed-up goblin in a tight bodysuit!