One of the most helpful mastermind or accountability group structures I’ve found is “Rose Thorn Bud”, it’s pretty straightforward:

1. Rose – What went well in the last week(s)
2. Thorn – What didn’t go well
3. Bud – But what could/should go well in the future

Make sure it’s extra defined and clear so it’s easier for the participants to be more accountable for their actions and goals.