Assessing the success of the event is a must and should be as close to the conclusion of the Golf Tournament as possible. Everything is still fresh in the Tournament Committee’s mind and mental notes that you’ve made can be addressed. Schedule a Tournament Committee meeting and come prepared to candidly scrutinize the pluses and minuses of the event. Did you start organizing early enough, were there enough volunteers, how did the marketing of your event go, sponsorship packages, registration form collect the data that was needed, etc. At this you should also be thinking about next year's event date, it's never to early to reserve your date. The buzz that you created with your event will keep everyone anticipating the next one.
A nice touch to close out your event is to send any sponsors that you received an appreciation plaque. Take your time in deciding on not only what to send but also how it looks. It should have a "wow" factor. If the event is youth related, have the kids signature laser engraved unto a plaque. Let's the sponsor know that these are real kids and their support helps them. But most of all, a personally signed thank you letter must go out to all sponsors and participants. For sponsors, make it personal. Include their name, what they donated and how it will be used. Maybe even include something about the tournament itself, especially if you played in the same group as a sponsor. Never send a cookie cutter letter out. The participant letter is just as important. Without them, there wouldn't even be an event.
One final peace of advice, never go backwards. Your goal should always be to top the previous years standard.
Doing your post-tournament assessment and mailing out your thank you letters become your twelfth and final success point.