Welcome to the whimsy puzzle making club! There are a few of us that make and sell puzzles, me and @jbmanning5 come to mind 
Since you already have started customizing a pre-generated jigsaw, you might be interested in getting into more fun shapes, which are referred to as “Victorian cut jigsaws”, since the style dates back to Victorian times!
I’m excited to see your continued puzzle creations! If you are interested in a free Victorian cut puzzle to play with or add on to, I shared one in the free laser designs section: Fall Leaf Halloween Puzzle *Update*