How much to tip my make-up artist?

I am getting my make-up done at a salon tomorrow for an event. They charge $40-how much should I tip?How much to tip my make-up artist?
10 dollarsHow much to tip my make-up artist?
I'd say at least 8 dollars, maybe 10 in they do a really good job.
At 15% It's $6.00 even Or at 10% is 4 bucks I would go with 25% % 10.00 take your pic and hope she does a great Job.