I have this theory that your first film is always your best film in some way. I always try to get back to that moment when you're not relying on things you've done before.
When you're dealing with a constant rhythm, no matter how great your lyrics are, if you don't switch it up, people's heads are going to start bobbing. And they're going to stop listening to what you're saying, so consistently keep the ear fresh and keep the audience surprised.