The most recent volume of The Scribes Journal of Legal Writing contains a wealth of helpful information for legal writers. 

If, like me, you sometimes need a refresher on the distinction between "that" and "which," the article by Richard C. Wydick, author of the well-known text Plain English for Lawyers, is the one to read.  (Hint:  "That" is for restrictive clauses and "which" is for nonrestrictive clauses.)  He also provides guidance on the more complicated issues of when dropping the word "which" or "that" can mislead the reader (termed "whiz deletion") and when the term "hereby" should be used.  Better yet, he includes practice exercises (and answers) at the end of the article!  True Confessions of a Diddle-Diddle Dumb-Head, 11 Scribes J. Legal Writing 57 (2007).

I've read about half of the articles in the volume so far.  Other articles that may be of interest to practitioners include the following:  one on drafting legal documents intended for lay readers by Wayne Schiess (page 1), one on mistakes to avoid when drafting contracts by Duke McDonald (page 25), two on ejusdem generis by Preston M. Torbert and by Gregory R. Englert (page 41 & 51), one, which also contains practice exercises, on nominalizations by Joseph Kimble (page 79), and one on Reducing Citation Anxiety by Darby Dickerson (page 85).

The Journal can be ordered here.  It is also available on LEXIS and Westlaw.