Learning to let someone sit and think is tough, especially since I always want to jump in and give advice. It's paying off, though. I think my "client" had time and space to really consider the problem she shared with me and the conflicts that were inherent in it.
The other part that is hard is to try to go to feelings and values. It's a lot more fun, and much easier, to focus just on "what'd you do next?" questions. But then, that isn't what is going to help people learn to solve their own problems, the heart of what this profession is about.