I tend to avoid "open" tournaments, and instead, encourage our students to compete in tournaments that use the USA Karate (formerly USA-NKF) or WKF rules. This way, at least you know what you can reasonably expect with a particular division.
For example, the way USA Karate places people:
0-1 years experience - Beginner
1-2 years experience - Novice
2-3 years experience - Intermediate
3+ years experience - Advanced
Someone who is a brown belt MUST compete in at least the intermediate division, and someone who is a black belt must compete as advanced. Also, any kata considered as a black belt level or higher (Seinchin, Kanku Dai, Jion, Bassai Dai, etc) cannot be performed in the novice or beginner divisions.
This way, you don't have too many people deliberately withholding rank, in order to get an easier division. Before they changed the rules in 2008, there were individuals with almost 2 years of experience doing black belt level kata, such as Seinchin, Jion, etc., in the novice division. People who want to compete in the novice or below divisions, must do a Heian / Pinan level kata.
Also, the referees with USA Karate are standardized in what they're supposed to know, which at least gives a more level playing field. I'm not saying it's perfect (there are certainly some bad ones), but at least it gives less wiggle room for those who would try to abuse the system.
To Karatemom3, I would try to find a USA Karate / USA NKF sanctioned event in your area.