This is wide-open territory and there are no rules!
I've noticed that clean input animations work the best for me. Here is a video showing what I mean by that, with some selection guidance. :)
I find short, complex, looping animations work GREAT for this process.
Ideally, your animation will be in between 30 and 100 frames. Instagram's compression algorithm hates analog noise. The less frames, the kinder the algorithm will be (assuming you have an end goal of posting to instagram.)
[ ] Any work or videos and snapshots of my work
sketches and gradients