I think I've been doing this for many years (mostly in school)... but anyway I always use the palm of my hand against my chin and press up and left then up and right to twist my neck (cause ya know ya gotta do it both ways). It makes a quite loud sound. People around my even hear it. They think it's weird cause they think I'll snap my neck or something but wow I don't think so. I use a bit of force sometimes but it just makes a loud crack. I don't know if this is any good or not... but it's just a habit!!