Every test I took, I learned of more possible ways Sun could test me.
I studied very hard and wrote down notes to organize everything together. For example, I would put all my session management pages or forwarding techniques on one page.
Class diagrams are important since they test you on exactly which class a method belongs to, like where methods from ServletRequest and HttpServletRequest.
When taking the exam, I was able to use the process of elimination to do well on the multiple answer questions. I actually felt that I could have gotten a higher score had I waited another week, but I wanted to get the test out of the way.
SCJP 1.4 - 93%
SCWCD 1.4 - 89%
IBM FileNet 3.5 - Developer
IBM FileNet 3.5 - Administrator