What does it take to have a great first conversation? While I can only guess as to what that is, I’m going to put my money on not having made any presumptions at all, not only for yourself but for those your speaking to as well.
This is way harder than it sounds. Most business-people will tell you that no conversation can be had without an objective at the outset. On the other hand, those interested in efficiency will say that a conversation where you rediscover the obvious is boring. For me personally, I tend to jump to intellectually-driven responses that can weigh the conversation down.
Occasionally I might get to point out some thing about or to the other person that will surprise them, not necessarily in always a good way or bad way. Perhaps its the discovery of a blind spot, or something valuable, not necessarily rationalized, but true. As in any magic trick you need your partner to make an emotional investment before this is even possible. Its the act of prioritizing our choices that prepares the context for a surprise. This is possible in the form of a question, or even an observation.
Conversations are still a very human act at their center. Practice always.