Whatever you do, don't ask me, "How's it going?" (or "How's it goin'?") if you don't care about the answer. I'm going to answer you, then ask you how you're doing. And if I ask, it's because I'm curious, and I would like an answer.
I'll stare at you until you answer, too.
So, save us both the embarrassment and just use, "Hello." or "Hi." or "Good morning." as a salutation. Okay?