Cliches are shortcuts. The more you avoid taking them, the more interesting the places you’ll end up.
Past mistakes
When you don’t think you deserve to be in the room, no one else will, either.
Getting stuck in a genre
The right genre is the one that will actually get you to fire up your word processor, rather than surf the internet.
Writing for VFX
The director, cinematographer and visual effects supervisor have the final say about what the effects look like. But until these people come along, the writer is all those jobs