There are many sites that have tips for writing law school and bar exam answers. You can start with memos I have written for classes, which include such tips:
Patent Law Fall 2007
Cyberlaw Spring 2008
Here are some other web posts that discuss exam answer writing:
Advice from Orin Kerr (cache)
Advice from Eric Johnson and others (cache)
Rick Hills's Exam Memo (cache)
1L Professor Tips (cache)
Creativity (cache)
Grades and Essay Length (cache)
Grades and Essay Length (cache)
Laptops and Exams (cache)
Patent Law Fall 2007
Cyberlaw Spring 2008
Here are some other web posts that discuss exam answer writing:
Advice from Orin Kerr (cache)
Advice from Eric Johnson and others (cache)
Rick Hills's Exam Memo (cache)
1L Professor Tips (cache)
Creativity (cache)
Grades and Essay Length (cache)
Grades and Essay Length (cache)
Laptops and Exams (cache)