Do not touch
be aware of your set and your patrons before you interact with them
watch your language, very few haunts allow you to drop the F bomb to customers
maintain your energy throughout the whole night same show at midnight that you gave at seven o clock
Remember that even though you have done the same thing 1000 times for each customer its the first time they have ever seen what you do. So do it right for them.
Bring a gallon of water...yes a gallon.
have fun, many haunt actors do not get paid, those who do do not make enough for all the hard work they do.
be patient, many of the concerns that the house managers and owners have at the start of the night are life safety issues and frankly higher priority than the fact that your costume is itchy or your mask smells funny.
Remember its a business, anything that would get you fired from a regular job will get you fired from this one...no texting between groups ya da ya da ya da.
Good luck, I have not missed a single haunt season as an actor since I started at ten years old, I love the work and would not have it any other way.