Year 11 parents' evening was good training for me although I was in a state of mild panic about my full day of teaching the next day. I basically sat and observed for a couple of hours and, given I have a Year 8 parents' evening in March, I needed to pick up some top tips.
First observation - the parents you really want to speak to don't turn up. This speaks volumes about the importance they attach to their child's education and how this rubs off on their kids. The parents of kids who are doing great do turn up and you tell them what they already know - "Johnnie/Lizzie is doing great and should achieve the grade he/she wants in the summer".
Second observation - the Dad in a suit, distracted by his Blackberry, their child's education only slightly more important than the urgent business he has left behind in the office and needs to get back to. He sits down in front of the teacher who earns a fraction of his salary and smiles indulgently as the teacher heaps praise on his off spring ("of course!") or sighs wearily as the teacher suggests a little more effort and a little less arrogance in the classroom would pay off ("what can I do about it?"). That was me.