It's hard to get a great outcome when your resources — time, money, attention — are spread thin. Are you concentrating your energies on a small set of targets?
Obscure questions are good, obscure answers are bad. For example, instead of asking "who directed the 1939 fantasy film Wizard of Oz" you should ask "Victor Fleming directed what 1939 fantasy film?" Everyone has heard of Wizard of Oz so they can at least guess the answer. Not many people have heard of Victor Fleming. Good trivia games should make players think the answer is on the tip of their tongue or smack themselves for not guessing that.