"Know thyself" should be the primary advice for PWS. I've made numerous comments about how I have learned to identify and resolve the psychological and situational factors that lead to my speech difficulties, moving from having a severe stammer to an occasional mild stammer. Something I've never been able to explain is this: my eye contact has always been lacking. Once, a friend told me when he looked at me while I was talking, I didn't stammer, but when he didn't look at me, I did. But because I could look at people while talking, I didn't know if they were looking at me. I've observed this even on the phone: I've struggled to speak to the other person, only finding out later that they weren't really listening, wanted to tell me I was speaking to the wrong person but didn't want to interrupt. Maybe there are subconscious cues, but certainly if someone isn't listening, I tend to stammer.