Here's the secret recipe:
1: Enter the massage premises.
2: When the attendant asks how long you want to stay, say "How much is 1/2 hour?". (This is the right amount of time for the first time, as why suffer any longer than that if she is terrible?)
3. When she says $40, you say OK, and give her $40.
By the way, she may ask if this is your "first time". You can usually get away with saying "no", which helps her feel more comfortable with you. However, she may then ask who you saw before, which may leave you hemmimg and hawing for an answer. I have found that admitting this is my first time at a spa ususally doesn't present a problem, and that some friendly and light conversation during the massage helps build their trust and "break the ice".
4. She will lead you to the massage room, and will leave you to get undressed and lie face down on the massage table.
Now, this is important - be totally nude when she walks in, and that also means do not cover any parts of your body with a towel before she comes in.
5. She will return, and may ask if you like a hard or soft massage. Just say hard, soft, or medium, as you prefer. She may then ask if it is OK to use oil. Again, state your preference.
6. She will then begin the massage. After about 15 or 20 minutes she will automatically change from the hard or medium massage to a soft "massage" which will consist of light caressses which will probably include your butt, butt crack, and some light tickling of the back of your scrotum.
7. After a few moments of this to set the mood, she will ask you to turn over.
8. Shortly after you turn over, she will ask if you want any "extras", or may phrase it as "where would you like me to touch you", or "what else can I do for you", or other words of that nature. (She may even ask you to take her hand in yours and place it where you want her to touch you.)
Note that, if you look like a policeman, she may ask you if you are one before any of the above questions. That phrase is usually accompanied by her saying "I don't want any trouble!". Be prepared to deny it convincingly.
9. She may then commence a price negotiation, and may even want the "extras" payment up front. Try to be friendly and kind.
10. Enjoy the fruits of her labour!
11. Don't forget to pay her the negotiated price. They don't like getting stiffed.
Hope this helps.