Layer art with dropshadow

I wanted to learn more about how I could use layers and dropshadow to give a piece some depth, I followed a tutorial for this. I ran in to some problems with accidental clip groups, I was able to solve this myself which I'm pretty proud of.

Tutorial: https://www.youtube.com/watch?v=Oi3tjyOSnOY&list=WL&index=4&t=814s
Reference picture koi fish: https://www.google.com/search?q=koi+illustrator&sxsrf=ACYBGNSZF23yOPFH_i7DO7VLtrSM8KxzfA:1579090324963&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjb1YzvyYXnAhVBiqQKHV3uAbMQ_AUoAXoECAoQAw&biw=1536&bih=722&dpr=1.25#imgrc=l39IreDyxMb65M