Makeup suggestions, please!

My grandparents and I had went into a casino and it's hosting this costume party on Halloween. As creative as I am I totally want to participate! The first place winner receives some cash too. My first thought as to what I want to be is either a mermaid or a fairy. I was doing research as to get some ideas and came across this makeup look. I was hoping the pic would include a makeup tutorial but apparently not. Do any of you lovelies have any suggestions as to what highlighter, eyeshadow, etc to use? It'll help me a lot! 💕