A few things you need to get clear before you start
Who will host the day?
Ask who is to be your host, ask to meet them on your essential reconnaissance and find out if they have been doing this for years or have recently been parachuted in as a friend of the owner. A day can be broken by a host who is more hail fellow well met and less well-informed guide, but you have to take some things on trust.
Ask about beaters and pickers-up
Enquire how many beaters are likely to be abroad in the land and how many pickers-up will be present. Some shoots populate their beating line with 10-15 individuals who are rarely seen or heard, whereas others have 20-30 on parade.
If you have asked the preceding questions and received reasonable answers then you’ll probably have a good day. If, on the other hand, you are in any doubt, then make your excuses and leave, because if it doesn’t feel right then it probably isn’t right.