I don’t know how many times I’ve walked into a store and the employee/owner doesn’t even acknowledge I’m there. That’s probably my biggest pet peeve. Always, ALWAYS, say hello within the first couple minutes. I think you have to approach each customer a little differently when it comes to how much you talk to them. We have some who like to chat, while others like to browse without being interrupted.  If you are polite and helpful, they will come back. If don’t have what someone is specifically looking for, we always give them the name of another shop in town or near by. They’re always very grateful, and often surprised.