Question about massage etiquette

Had my first ever erotic massage in Thailand. I'm more a bottom. I went to Mystic Orient in Chiang Mai, because it was close to where I stayed.
I came in and the receptionist explained to me that the minimum tip was 600 baht in addition to the massage price. That was ok with me. What was unclear to me, when does one negotiate the things one wants to do? For example if I want to get fucked, when do I say it and to whom? What about the price/tip, will I have to increase it?

In this particular case, I didn't negotiate the sex practices, so just went in and was given a great traditional Thai massage (the receptionist claimed that the guy, called Mak, had 4 years of experience - I thought it was quite possible, also I thought he may have been towards 30 years old - ok with me). Then at some point the masseur rubbed his dick on my head and so I just started sucking him and then he helped me get myself off by licking my nipple and playing with my asshole. Was great, I increased the tip to 700. Still I wonder when would be a good moment to negoatiate what I want and the price.

What do you think what is the best place in Bangkok for a bottom to look for a good top?

[RonanTheBarbarian]

In Bangkok, probably the best massage places for more masculine, well built guys are Hero (Sukhumvit Soi 11) and the Body Club (Sukhumvit Soi 8).

In the Silom area, Fan club massage (in a lane off soi Convent) had plenty of masculine looking guys the last time i was there.

They will not necessarily all be tops but more likely to be than places with more boyish or feminine lads. When you are choosing your masseur, (all of the above are big places where you would have plenty of choice of masseurs) you could probably ask the captain to recommend a top.

As for tip, well I think Hero has a 1000 baht minimum tip policy. In BKK, you would be expected to tip at least 1000 baht for a massage which includes sex.