You always think you can do better. No question about that. In a way, you want to try and do every aspect better.
The 60's has its own particular style and I think setting film in a period enables you to create your own reality that the audience can escape into and have fun, and in a way make it more real than it actually is.
There's something about being there, on the set, in costume, in the moment, where you start to get a feel for the scene, which is not the same as sitting in your office writing it.