I'm assuming it's for off-road so ....
Fun tracks with big jumps, wall-rides and always different layouts with anything goes type attitude seems popular with members and helps promote a good fun atmos ....
We always run a summer and a winter championship, 5 meetings over 5 months, with 4 to count. And each heat with a "bump up" Its surprising how competative peeps can be and won't want to miss championship rounds.
Our summer series is usually run as "drift" racing with cut up inner tubes for tyres. Its cheap, very different and VERY popular.
I would also say don't worry about trying to include all classes, peeps will generally go and buy whatever class you race ....
HTH
