One pro once said if you can go shooting for a day and come back with just one awesome shot then you should feel proud.
I think thats very true, I usually have a good ratio of keepers, but when shooting digital that ratio drops a lot, on film though, specifically when I'm shooting w/ my medium format stuff, I find that my shots are more deliberate and thought out, so I tend to walk away satisfied with a lot more of my shots. As I've heard from a few others, the only way to improve is to keep shooting.
It is difficult sometimes; you want to capture it all and are not sure where to start.
absolutely, I have one friend that whenever I really like a place I try to encourage him to go since he has a way of capturing the feel of a place, whereas I tend to look for more artsy shots and forget to take a few of just a room.