Sometimes I do this thing where I give a pop quiz.
The first time I do it, everyone panics, because I'm not a pop quiz type. Then I say, "no, no, it's ok. It's a review quiz. Don't worry." Everyone gives me this look like "What in the world are you talking about Mrs M? Are you crazy?" and I explain.
A review quiz is a pretty simple idea that always amazes me with how well it works. I give the students a quiz. It's all identification, short answer questions so that when I read their answers I really know what they know. They spend some time taking it like a real quiz (books and notebooks out of sight, no talking, no questions asked.) I tell them they can get out their notes and they switch pens and start looking up everything they don't know. Eventually, I collect them and take them home and look over them, marking them up with corrections and suggestions but giving a lot of leeway in grading.
I'm always surprised by how motivating they seem to be. I'll get a few students who just keep working with their books closed even after time is up, because they'd rather remember it than look it up, and eventually get it all. The majority of students will have to look up about half of it, and I can get a feel as I walk around about what's been working or not lately. A few students will have almost nothing on their paper at first, but rather than give up, they work diligently to figure it out when it's notebook time.
This also gives me a good chance to fix misconceptions, point out common errors and take notes on what to review before the actual test. Great for long units like the current one (World War 2).