How often should you get a facial?

Whenever someone asks what I do for work, my response is usually followed-up with questions about pressing skincare needs, such as: 

How do I get rid of this spot (don’t touch it!)?
What can I do to keep from ageing (use sunscreen EVERY day)?
Do I really need to wash my face in the morning (1,000 times yes)?

One of the other common questions I’m asked is how often to get a facial.