for my cut out I used the magic wand around the red starfish, I placed it on the top background paper and erased the middle section showing the bottom brown/sand coloured background paper.
I did this 4 times different sizes and poked smaller red starfish through the cutouts

Kit used is Ocean Breeze Kit by palvinka designs

https://pickleberrypop.com/shop/Ocean-Breeze-Kit.html

photos of my children in the pool during last summer
(cant wait to get the pool out again this year)