First, I spent awhile making the physical outfit. I used a bikini bottom and a strapless bra. I bought foam pieces and cut them into various shapes that were similar to Mystique’s scales. I glued the pieces over the bra and swimsuit. I also had some foam sticking from the top of the bra, to try to hide the typical bra shape. After the glue dried, I put a couple coats of blue body paint on them. I did this a week before I actually wore the costume.
The day I dressed up in my Mystique Costume, I put on the top and bottoms. Then, I had my yellow contacts put in. Next, I used red spray paint to coat my hair and make it slicked back. Then, I had three layers of blue body paint applied to my body. I had to stand with my legs apart and arms apart to allow the paint to dry. It took an hour for the paint to become moderately dry. The issue I was having mainly was my arms and legs sticking together and ripping the paint off. I used powder makeup on the inside of my legs and arms, it seemed to stop the sticking problem.
Then, had scales airbrused to my body using regular airbrush paint and acrylic paint watered down. There are two different shades of blue, white, and black paint that were used in the airbrushing. Overall, it took about 7 hours total that day to get fully into costume. It was well worth it I think.