Diy Ariel Costume . The process for making the ariel dress, step by step is exactly the same as the diy ursula costume, the only obvious difference are the colors of the tulle, the crochet 6 inch. You also can become the legendary character in the children’s cartoon of the same. DIY Mermaid costume galavantgal Mermaid costume diy, Mermaid diy from www.pinterest.com It consists of two sewn items and 3 purchased items. To achieve this look, but with some renaissance flair, my plan was to dye our base costume blue and add a black corset. The process for making the ariel dress, step by step is exactly the same as the diy ursula costume, the only obvious difference are the colors of the tulle, the crochet 6 inch.