Try not to get consecutive appointments - leave at least 5-10 mins between. Depending on how the queues are organised be prepared to give up on a teacher who is over-running seriously to get back on track with another who is keeping well to time, or even (if there are two of you able to attend) split up. Go back to the slow ones later, or phone the school the next day and arrange another time. If your son hasn't managed to make appointments with all the teachers make sure you at least know the names of the others so you can spot if they are looking lonely and you can jump in! Take a book/ newspaper to read, or get to know some of the other Year 7 parents if you don't already. Don't take younger siblings if you can possibly help it. If there are any subjects you have particular concerns about, write brief notes in advance so you don't forget that vital question. Be tolerant if the teacher doesn't immediately remember your child - they may have several with the same name and yours will only stand out if particularly chatty or problematic. Try not to eavesdrop too obviously on the parents in front! Take a bottle of water....
agreed - could swap the water for a St Bernard carrying Brandy if there are lots of stairs to go up and down
I also find that you have to be flexible re appointments, as you say, jump in if there is a slot and if you have to wait for one teacher for a long time then just catch up with the others later.
DSs school was curious in first year - we all saw form tutor but subject teachers were seen to some extent "by invitation" - though you could see them if you wanted. - turned out that if you got no invites then things were going fine and it was a bad sign to get too many invites.