If your intent is to make a positive impression, there are tried and true ways to do this that are relatively universal. As lil says, #1 would be to listen. Some other advice:

Ask interesting questions. What do you think the weathers going to be like? isn't the kind of question that makes any sort of impression but If tomorrow is sunny and 80 degrees and you could do anything outdoors, what would you do? is the kind of question that makes a positive impression and can lead to a far more interesting exchange. Make the conversation easy but not forgettable. Don't "interview" but do "discuss". Don't have a litany of questions but let the conversation flow natually, find some common ground (like you did with the grocer re: animals) and develop your relationship there. Equally important is uncommon ground. Maybe they have a hobby that you are interested in learning more about or vice versa. -This is how friendships start. You've never been running before? I know a great trail for beginners, what are you doing this Saturday? The key is to be genuine. The moment you start acting scripted or think too much about how to construct a discussion, it will falter.

I really enjoy having conversations with people and I have been told that I have an ability to motivate people towards a desired action (sales). My wife calls it being a master-manipulator but my VP calls it being a top-performer. Strangely enough, I prefer his interpretation.