What should I say?

There's this guy at a drive through I go to sometimes. We've seen each other since last fall, off and on, and I think he is beginning to remember me. He recently guessed my coffee order, I was flattered. :) And he said Hey too, as if he recognized me, a few weeks ago. I'm REALLY shy, but he's kinda cute and very nice.
What can I say besides, How's it going? I've only said hello and thanks and have a good one.... I would like to branch out from there but I'm so Dang Shy ..ughhhh