Must Be Earned.
If you wait to be inspired before you start writing, you most likely will wait for a very long time. That bolt of soul-clarifying insight usually doesn't happen while you sit around waiting for it.
You have to write.
The physical act itself will free the imagination.
There's a technique known as stream of consciousness, and that should be the strategy of your first draft. Whatever words flow into your brain, let them continue to flow through your fingertips.
In theory, at least in its initial phase, writing is easy. One word after another. Inspiration usually comes mid-sentence.
Your muse will sing, but only when you're already on stage.