In my somewhat limited cyclocross experience, what makes for a good venue includes the following:
1) The level of competition
2) Challenging race course, following UCI/USAC standards
3) The intangibles
The level of competition is important if you race seriously, because individual results are weighted according to how strong the field is. This ultimately determines one's handicap, which is important for races that follow call-up procedures based on points. Therefore, although standing on the podium is exhilarating, a lower result in stronger field can end up being better in the long run. This is true even in local races. For example at last year's Omaha CX weekend, I was second on day one and fifth on day two. However, due to a stronger field that showed up on day two, fifth place on the second day was weighted heavier, resulting in similar handicap points.
In other words, if you can choose between two races (Category/Masters), pick your races wisely. If your goals are short term, then going for cash isn't a bad option. Otherwise, a better starting position in a future race would dictate picking the harder race, even if it means a much lower place.
Part of what draws good competition are a challenging course and the intangibles.
As for the course, it must follow USAC or UCI standards. The standards are not only published in the rule book for consistency among race venues, but they are there for safety purposes. For example, courses should be 3 meters wide throughout the entire course. Another one: courses may also include a single section of temporary, artificial wooden barriers up to 40cm tall, between four and six meters apart. I have pointed out and asked officials to remove a third barrier before. It may sound appear elitist to do so, but I'm sorry, that's bush league, and it seriously undermines the validity of the race venue.
The intangibles of a race venue will also attract/repel competition. Location (big city/rural) is unfortunately part of the deal; small venues have it harder this way. But smaller venues can do a lot to ensure they're race gets put on the calendar year upon year. Cash prizes are always nice, as are deep field (10+) payouts.
What else? Swag, food, refreshments, live music. Clean, plentiful toilets. These are all standard fare at good races.
What else can a promoter do? Offer a pro clinic to all participants. This is what I experienced at the Gateway Cross Cup in St Louis last weekend, where Ben Berden and Nicole Duke put on a top notch race clinic for anyone interested. I picked up several tips at this clinic, including better turning techniques. In fact, applying what I learned the day before allowed me to pass six in a single turn on the first lap. The clinic was worth the trip in itself. And it was the best value (free!) of all.
Good competition follows great venues and intangibles. Last weekend's Gateway Cross Cup has all of that. It's why it's been on my calendar for the past two years, and will continue to be so.
Thanks for reading. Happy Friday.