I would point you to this thread:
https://eccie.net/showthread.php?t=2635919
Or specifically this post:
https://eccie.net/showpost.php?p=1061649482&postcount=8
My advice would be to start undressing immediately, be sitting up rather than laying down when she comes in to start the massage, bonus points for Little J being at attention. Don't lay down with your arms at your sides -- let them drape over the sides, and if you get a chance to stroke or caress her leg, do it and gauge her response. Lastly, your mannerisms and comfort in the situation will be a big indicator for her, be relaxed. A little conversation goes a long way. If she laughs, you're golden.
Good luck.
Edit:
Read post #8 in https://eccie.net/showthread.php?t=2635919 lots of good information.
Originally Posted by Liekki
Shit, beat me to it!