Write a scene introducing a character who looks human but is actually a dragon -- without revealing their secret. Describe their movements, the quality of their voice, their quirks. Anything that a reader would later recall as clues when the secret is later revealed. Include dialog. Perhaps the dragon is a shop keeper, a client, a new neighbor.
This reminds me of a wonderful book, Tea with the Black Dragon by R.A. MacAvoy. I don't think the sequel lived up to it, but this one had a lovely relationship between the main character and the man who aids her in her quest for her daughter, who may or may not be a 2000 year old Chinese dragon.