Outling in law school is an artform...it really is. It's about getting your notes, the elements of the law, sometimes policy, and always your professors words---down in paper form that is easy to read, and easy to memorize. Now outlining for a closed book exam is a little different from open books, but not much.
I start with the professors syllabus and how they break up each class period, as my heading. I start with the elements of the law. So for torts, say, negliegence: duty, breach, causation/proximate cause, damages. Then, I break it down into the cases we have read for each section and how the court [the Supreme Court that is] has broken down the elements. The case name, the page it is on, the holding. Sometimes if facts are important, the key facts. Followed by the policy. Followed by what the prof has said about the law.
As I complete my outlines, I will post one on here so you can see what I mean, or at least parts of one!