Well, one tip I can give is that I find it annoying when someone asks to befriend me who is just trying to drum up business for their Tarot reading business. I don't buy readings----can't afford the expense----and anyone who knows me knows that so having them just befriend me to get business for themselves seems not only kind of rude but also like they're taking advantage of other people's facebook to spam everyone else. That's my two cents on using Facebook to get business. I wouldn't do that to someone else so I don't like having it done to me and I've stopped adding those people as friends if that seems like their obvious only reason for adding me.
If you're in the business of reading, put it into your profile or something and leave it at that but don't spam the rest of the Facebook world with it. I'm sure there are many other people who feel the same way I do. We're bombarded with spammy stuff all over the internet, every which way we turn, we don't need it on Facebook, too, more than is already there along the sides.
That's my personal feeling about it, but my professional feeling is the same. I wouldn't do it other than putting it into my profile. There are few places where people can just socialize with their friends and peers. Here is one and Facebook should be another one.