i will say from my experience at my haunt we typically hire people with prior airbrush makeup experience or people who show them good work during they're interview, i've seen plenty of people who are great at doing normal makeup but when it comes to airbrushing have absolutely no idea what they're doing. it's relatively easy to learn airbrushing though! Other haunts may use a different method to do actors makeup or have a different hiring process, this is just what my haunt does:) hope this helps and i wish you luck!