Linda Aronson (who wrote Screenwriting Updated) points out that the creative mind is not proactive, but reactive. And it reacts to triggers. More (and more varied) triggers will result in more ideas.
In practice this means that if I say 'write a joke'. You have nothing to work with. No triggers means you're trying to make something out of nothing and you'll find it very hard to write a joke.
If I say 'write a joke about a Mexican'. You have one trigger, and you'll write some jokes.
If I say 'write a joke about a Mexican narcoleptic' you'll write even more jokes-because you have more triggers.
If I say 'write a joke about a Mexican narcoleptic continuity announcer' it gets even easier because your reactive imagination has lots to work with. You're not staring at a blank computer screen hoping that your imagination will proactively find something for you.
So here's a challenge to all you insomniacs:what can you do with the triggers we've been given?
Namely:
A large fat pheasant (Deceased of course).
A dildo (combined with a 'loud buzzing' sound effect.
A fishing rod.
Go on. You know you want to.