Refrain from alcohol and recreational drugs the day of the meeting. Refrain from giving advice and criticism. This is a must. If a member requests assistance, it is best to volunteer it at a private meeting between the two of you at another time. A phone call also works.
Confidentiality is paramount .
This cannot be over emphasized. This includes talking to your spouse or significant other about who said what in the meeting. Nothing discussed in the meeting goes out of the room. If a confidentially breach is discovered is it wise to ask the guilty party to leave the group. No subject is taboo.