Agree I have seen some amazing MLs and I have a few regulars but I am always on the look out for new ones!
Generally Try and build a connection, treat the girls nice, tip generously but not over the top
I think I mentioned in another thread first visit to a girl I won't ask for any special extras but hint at them and based on reaction in the second visit you can just ask for what you want.
If the ML rejects just smile and continue to enjoy the rest of the massage.
I have had MLs reject me initially but agree to FS in a subsequent visit.