I made this costume because the mermaid costume I wanted to buy only went to size 10.I combined a lot of ideas from the internet. Its 2 separate pieces. The top is a steel boned corset in beige .I added pieces of the skirt fabric to make it look like it flows into one piece. Shells from a craft store were sprinkled with holographic glitter. The skirt was made from fabric I bought online. I created a pattern using brown craft paper and cut fabric accordingly. Once the skirt was sewn, I added net mesh to fluff it out so I could walk, and coordinating colors of organza fabric cut into strips to the bottom. I made the two larger fins by creating a pattern, cut sequin and leather using that pattern. I sewed them together and left the top side open and added a piece of cardboard to each to stabilize them. Then I attached the fins.