What makes a good server/waitress?

In your opinion, what are some things that you look for in a server or waitress when you go out? I am currently starting my first waitressing job and I am very nervous. This is my first time being a waitress. I just wanted to get first hand advice from consumers themselves! Do you like one that greets you? Do you like when they smile often? Etc! My goal is to make sure my customers cups never go empty. Opinions and advice greatly appreciated!!