A background actor is very important on a set, of any kind. They help fill out the background in a scene, and give more context.
To be a good background actor you need to keep a couple things in mind.
There will be a lot of waiting around on set, for the crew to get everything into place, for actors/actresses to be ready, etc. Make sure you listen to ALL announcements made, and be ready to go on set at a moments notice. Do NOT make them wait on you.
2. Be Professional
No matter how much you are getting paid, or how long you are there for, be professional. There is tons of money being spent daily on productions, show up at the right time, bring the correct clothing and be positive.
3. Get to know some key terms
Blocking: Refers to the placement of the various actors/actresses and extras in the shot.
Marks: Refers to the specific spot of which you are to stand during a scene.
4. Paperwork & Pay
For most sets, you will need a drivers license and social security card as proof you are legal to work. When you first arrive on set, you will check in, and from there they will give you the necessary paperwork you need to fill out. Make sure to keep your copy of these documents for your own records.
5. Be QUIET
No talking, rustling around, opening/closing doors while cameras are rolling.
6. Things not to do
No asking for autographs.
No behaving like you are star stuck.
Do not bother the director.
Do not try to give actors/actresses pointers.
We hope these are a couple tips you can keep in the back of your mind when being a background actor on a set!