Raid: I know we all approach photography differently. One thing I always insure that I never want to think about is how much film I have left. So I always bring twice as much film as I think I can possibly use.
I tend to shoot quite freely until some focus of the overall theme comes to mind. If you do not have an overall theme, one ends up with a series of random photos with the only thing in common being that they were shot in the same geographical area. Once I get an overall theme for a series in mind, I then tend to be more selective and only shoot those things that fit into the theme.
You mention 8 different emulsions. I only shoot with one but know others see differently. With so many choices, how do you ever arrange to have the right one in the camera at the right time?