It's difficult to acquire grades when utizlizing writer's workshop. In addition to monthly published pieces, consider adding a weekly cold assessment to your plans. See example below:
Lesson 26 from Cunningham, P. (2003). Big Words for Big Kids: Systematic Sequential Phonics and Spelling. Greensboro, NC: Carson-Dellosa Publishing Company, Inc.
*According to Robert Marzano, highly effective teachers use similarities and differences in their classrooms. When sorting and transferring, you are finding similarities and differences. :-)
This is typically a two-day lesson. You have students make the words the first day, and sort and transfer the second day.