I clap with the back of my right hand slapping the palm of my left hand (Bajoran style). I don't know why but it's how I've always done it. For some reason I really hate the feeling of my palms and finger undersides touching each other.
I clap really loudly. I cup the fingers off my right hand and bang them into the palm of my left hand. Sometimes people are annoyed by my choosing because it's so loud. But we're clapping? It's supposed to be loud?