Once you know how to talk, the second step is knowing when and about what to talk or not talk. The whole point of small talk is that you use it as a means for finding something that one of you enjoys talking about that the other enjoys either listening about or also talking about. Conversations tend to have a mind of their own, but everybody conducts them a bit differently, so a hard rule would be a disservice to you, but you need to develop a good sense of when to let the subject change. The smaller the talk, the more important it is to let the conversation roam. Search for shared experiences and if anything they say reminds you of something, then try to lead it off on that tangent.
Being a good listener is perhaps the most important part of banter. When the topic gets toward something that can be talked about, get a good feel for what their thoughts are by letting them go ahead, with occasional prodding, and then when the time feels right you can complete and extend that line of thinking yourself. The person will feel like you understand them, and will thus be inclined to move the conversation toward more substantial subjects and a more intimate tone. It needs to go both ways, of course, so make it easy for them. Two people doing this to each other over the course of a sufficient length of time will culminate in marriage, provided they don't piss each other off too badly beforehand.
