How do we define a practice? I believe there are hundreds of solid practices that many, even most, law departments should recognize and contemplate for their own department (See my post of April 2, 2005: survivor bias and best practices; July 14, 2005: the most important practices are the hardest to imitate; Sept. 13, 2005: how easily we overlook common good practices; and May 30, 2006: our bias toward novel practices.).
At what level of specificity do you define a practice? A practice is to file important documents; a sub-practice is to track those saved documents so you can search for them; a sub-sub practice is to prepare red-wells and labels for those documents; a sub-sub-sub practice is to send some of those physical files to long-term storage; a sub-sub-sub-sub practice is to negotiated 24-hour retrieval times with the archival company. An analyst can keep breaking down practices into smaller components.
Do practices stay still, butterflies pinned to a page? No, practices evolve (See my post of July 15, 2006: Horndal effect of gradual improvement; and June 20, 2007 # 1: Horndal effect of increasing productivity.).
Is every process a practice? If so, both of the points above are doubled. The distinction between a practice and a process is elusive (See my post of July 13, 2008: processes pulled together with 26 references.).
Come to think of it, the number of law department practices that someone could attempt to catalogue must surely be in the thousands.