There's always lots of energy at a fashion shoot. The models love to have themselves photographed and it makes things easier for the photographers. Only problem is when there are too many photographers and/or the venue is too large for the space provided.
Using the "critical lens' of my camera, I find that I get better shots when I catch models unaware or not setting up a pose. An especially tricky thing is to get a model to pose in a way that reflects what the photographer has in their imagination. Very rarely does this happen but when it does, the photos turn out great!
But in summary, there aren't too many other things as pleasurable as photographing beautiful people.