A woman should make herself as much in demand as possible - looks, menu, performance etc. Then, she will have more leverage with her employer. Secondly, women should work towards going independent. Work at a spa and build a reputation. After she has a large enough following, go independent and make double what you earn at the spa. Set your own conditions, your own hours, your own boundaries and see only who you want to see.
And ladies have to remember that the spa doesn't make the lady. The lady is the one that makes the spa. No one visits a girl because of the spa. They will see the lady, regardless of which spa she works at. If she is good then even if she goes independent or moves to another spa, her regulars will follow her and adjust in order to see her.
I would never book an ugly, low mileage woman just because she works at a reputable spa.
Take Daniella. She could move onto another spa, but her regulars would travel far to see her again, regardless of the location. She is that good. She is the #1 MPA in the GTA right now. Everyone who sees her raves about how great she is. She doesn't need Premiere in order to do well in this industry. Premiere needs her, not the other way around.