There has never been a sure bet recipe for me to climax. I have had very vanilla moments that have brought me to climax, and some very non-vanilla moments that did'nt.
I'm sorry for my boring answer lol, but it usually boils down to my level of attraction for the provider combined with my perception of their attraction towards me (I did say perception) combined with a little spark in the moment (could be many things) that puts me over the edge.