A couple more from the toolbox:
K-I-Q: Especially at the start of a semester, I find it clarifying to work with students on making distinctions about what kinds of processing they are doing when they respond to a reading or any other object of attention: a work of art, a problem-based scenario of any kind. There are three to start with: making observations, drawing inferences, and asking questions. The three relevant trigger questions are: What do you know for sure? What are some things that you may not know for sure, but that you are reasonably certain are good inferences? And finally, what do you need to figure out, what is still open to question?
Analogy: How does the situation you are looking at compare to anything else you may be familiar with? Explain situation A by drawing an analogy to situation B. (Student examples here.)
Juxtaposition: This is a slightly different take on analogy: take two things that may look dissimilar and think through their interconnections. One form is simply comparison/contrast.
Visualization: Often it's true that a picture equals a thousand words. A number of blogs I have looked at recently are referencing this übercool inventory of graphic organizers: you have to see it to believe it.
Reflection: As a followup to many assignments and classroom activities, one of the most clarifying exercises is to ask the students to finish off with a reflection paper (or perhaps a conference), in which they can explicitly think back over and debrief the process. It might a reflection done in regard to a specific process, like reading a poem or writing an essay, or finishing a video project, or it might be more generally a reflection about the overall learning goals and where one stands at the moment, as in these end-of-the-third-quarter reflections about critical thinking itself.
Okay, I could go on. But this is a preliminary listing of some useful tools for directing student's attention not just to what they think, but how they think, and how they might go about thinking better.