Make sure it's legal to hold a submission grappling/BJJ event in your state. Nothing like getting shut down at the 11th hour because someone at the athletic commission doesn't understand the sport.
Also, when you're planning your schedule, build in a little bit of a buffer. You can't control everything (imagine having 6 mats and one of them having a guy with a fractured arm on it for an hour or so before the EMTs can move him). That's going to cut into your schedule, so you need to be prepared for things like that.
Schedule advanced/upper belts before lower belts. Nothing like coaching for 6 or 7 hours and then trying to compete after all that.
Invest in good referees.
Making brackets ALWAYS takes longer than you think it will take. ALWAYS.
Don't think that will be an issue .. I out rank the State athletic commisioner I will choke him unconscious the night before