I think this thread so far has the right elements.
First off we need 4 or 5 fights, even if you are only going to do 3 live and use 2 from the prelims.
Second, start the card of with lighter weight classes, specifically two strikers with decent ground games.
Third, get some name recognition in there that never have boring fights. Faber, Forrest, Guida, Bendo, etc. These guys even go to decisions and people talk about how exciting the fight was.
Finally, try to guarantee a finish in the final fight. Very rarely will people watch a 25 minute decision and like the fight they saw (Hendo vs Shogun being one of the only exceptions I can think of).
As a bonus give us JBJ fighting for free