I think Its OK to make It up or add your own ideas. It's a craft and more enjoyable. If you already Crochet then you have learned a variety of techniques. Just go for It. What's to lose? When wanting a different edge, I try the Picot Stitch It works well.
How do you not make the white yarn tight? I'm doing it exactly like you but the white is not wavey. The white folds down against the green because of how tight it is