Hiring an albino person to bite someone and run away, then every night sprinkling Molly on their food. During the night they will be high-ish with a good sensation sweeping over their body, but in the morning as the Molly wears off they feel down and unmotivated. Repeating this constantly for multiple nights/forever can lead this person to believe they are in fact a vampire.
When you find a person that is begging to be made fun of while driving, you roll down your window, call them out based upon their general appearance, and when they look at you, you yell as loud as you can BLAUGHHHHHHHH like a vampire.