1. Find a TA that has group rates and suggest everyone use them to get the group discounts.
2. Do not try to get your cabins in the same area. I know it sounds good, but it does not make any difference. Plus pricing may be an issue.
3. You can not eat dinner at the same table and do not try to control who is together at one table. Maximum table size is 10-12. Even if your reservations are linked, do not assume the MDR has the links.
4. Let everyone book their own excursions. Don't try to control their day.
5. If you really get 70 passengers, try to get your own meeting area. You will not get 50-70 seats in any bar venue.
6. Publish a list of everyone's cabin #.
7. Suggest everyone fly in the day before and stay at the same hotel.
8. Make sure everyone has the proper documents. (a passport and, if necessary, visas)
9. A good place for a family reunion picnic would be to book a cruise with COCOCAY as a stop.
10. Christmas and Thanksgiving cruises are very expensive. As I posted earlier, pick a ship and date and stick to it. If there are children book Quantum or Oasis class.