I read a lot of legal writing, but I also read news, nonfiction books, and other professional writing. Some of the writing I read is not so great. Here are the most common writing problems I see across all forms of professional writing, not just legal writing:

• Using bigger, more abstract, and more complex vocabulary than necessary.
• Writing sentences that are too long.
• Using noun forms where verb forms would be better.
• Using passive voice unjustifiably.
• Failing to catch small writing mistakes.
• Using unwarranted variation.