I use this worksheet before any writing activity so that students read examples of the type of writing that we're doing. It is a chance for students to take the time to break down examples, looking closely at some aspects I will be focusing on when grading their work. This can be used with any type of writing, nonfiction or fiction. This is also an effective measure of reading comprehension and critical thinking.
This assignment is something I use for the prewriting stage for all of my writing assignments. It forces students to slow down and make their thinking and writing more conscious. If possible, it's a good idea to let them choose the writings they'll analyze. Or, you might assign one and then let them choose the second. (This worksheet requires an analysis of two writings in the same genre, so students can compare/contrast technique while analyzing). This can be a library resource assignment with actually texts or something they research online. One fun assignment is to have them analyze introductions to cookbooks and then write their own.
After finishing, we compile all of the effective techniques they found from their analysis, and I grade them on that discussion, so I get a better sense of how much effort they put into this. It also allows the class to create a long list of effective techniques they can later use their writing.