I am interested in how to approach a cute waitress?

First make sure she is not married. Look at her left hand and ring finger. If she has a ring, engagement or wedding ring on enjoy her beauty but leave it alone. Make sure you are presentable, clean cloths and not tore up, brush you teeth, hair combed, and don't have an attitude presence. Just say hi to her as you walk in to the restaurant if she is around and not busy. Sit at her table of service and wait for her to serve you. Be upbeat and positive in your manner and smile in a warm manner. Just tell her that you came back for more than just coffee, a coke or food. Tell her "I saw something special in you and was hoping to know more about you but didn't want you to think I was a weirdo, but just a guy who noticed a quality girl, not much around anymore. Would you be interested in sharing your break with me for just a few and get to know me and I you?" If she is hesitant then acknowledge that and tell her I won't give up easily but I'll probably see you again tomorrow. Being persistent pays off dividend. Good things take time to develop, like Diamonds. Keep going back and then she will know you are serious and not just a player. If she tells you "NO or I'm not interested", then you gave it a shot and you can feel good knowing that you didn't let the opportunity go by. How many times have you looked back and said, "woulda, coulda, shoulda"? The worse thing that could happen is she say's NO. Nothing lost a lot to gain.
Wish you the best.