As both a writer and teacher of writing, I have found no better method than the Six Traits model when it comes to planning and delivering meaningful, effective and practical writing instruction. Thanks to organizations like Education Northwest (formerly Northwest Regional Educational Laboratory) and Northern Nevada Writing Project there are a number of online communities of active and reflective practitioners who are constantly sharing resources and best practices. As written in a publication from Education Northwest:
There are probably 50 or more versions of the six trait model in existence today. The trait model is used by teachers, primary through college, and not just by those who teach English either. The traits are used by teachers of mathematics, science, social studies, foreign language, special education - anyone for whom writing is an important part of instruction. (from Instructional Manual, 6/28/11)
As revisions and new instructional materials continue to be developed by teachers all over the country, I will continue to be a student of this approach to teaching writing.
The rubrics are the core of the Six Trait model; here is one of the web's best resources: