Many people are sceptical about hypnosis, mainly due to misinformation from the media, and even practitioners themselves, as to what the state is and what can be done with it. This is where Erickson's indirect/naturalistic approach is so handy. I was going to do a bit on hypnosis and healing, but it might be useful to cover that first- thanks for the idea
On the stop nail biting front I have done habit management with clients. With nail biting it can be useful to find out the reason, or just displace the habit, depending on the person and situation