There are a few threads that list stories you can tell .. but improving your dialogue with others can really only come with practice and self-awareness of what you are saying. Try to base your discussion structure on the theories in the mid-game and routine sections (disqualifications, etc.). The biggest piece of advice I can give you is to NEVER ASK QUESTIONS! Instead, you want to make statements. For example, imagine you were to enter your local gym and an HB was working the front desk. Most guys would start off by asking questions like "how long have you worked here?" and "do you enjoy working here". This is not a conversation, it is an interrogation. Instead, make statements .. such as "I can tell you enjoy working here, I've never seen you without a smile". In this example, the HB will probably smile after your statement (bonus

). Also, never answer a girls question directly. For example, if she asks you what you do for a living, you say that you are a disposable lighter repairman (or something along those lines; props to Style).
Always remember that the key to a girl's heart (or pants) is humor.