Just one idea is you could always say "Oh, actually I was just thinking about X." And then that gives you free reign to launch into any kind of story you wish. And you can ask things like "Have you ever wondered about X?"
This way you can add some substance, tell some stories, and add some indicators of value in there too.
Of course you should only do this when you're being asked "How are you?" in a situation where a conversation is starting. If you do that when someone is just passing you in the hall and giving a token "How are you?" you'll look a bit strange.
