Parents that that were unhappy with tryouts, why? What were you looking for? Give details instead of saying it was bad. What was done that left such a negative feeling. And the ones that were happy, why? What did that team do that impressed you so much. Maybe this should be another thread to help out both sides in the future.
Some random things:
1) I would say be prepared, whether it's 1 or 100.
2) Have a back up plan if you get overwhelmed.
3) Make sure every girl gets a fair evaluation.
4) If you are interested in someone don't walk out to talk to her parent(s), and forget about the other girls that you didn't see yet. You might miss someone possible better.
5) These girls show up for 2-3 hour tryouts, at lease give them a chance to prove what they can do, or not do in some cases. Give them your undivided attention.
6) Don't rush through because of your poor planning. But at this point, we may on longer be interested in your team.
7) I do like to see evaluators at every station taking notes and making sure they have the right players number. I even seen a few evaluators correct some mistakes girls were making, possibly to see if they were coach-able?
8) If you post a tryout and only need 1 or two players for particular positions, please say so. It will save everyone a lot of time.
9) Have a question and answer with the parents. This way 30 people aren't standing in line to ask the same questions 30 times.
10) I like to see coaches involved as much as possible. You are trying out to be my daughters coach, as much as she is trying out to be on your team. Coaches you are being watched also.