Link to a fairly decent grouping of strategies to keeping your essay and critical work on track and engaging. I have found it especially useful in trying to complete my academic coursework, and plan to use some of these strategies on non-fiction work of my own, looking at writing itself.
At least worth a run-over for students, both high school and post-secondary level.
Especially useful bits are the heavy uses of examples. I like the editing bit and conclusion sections especially.