"If you read a piece of text through 20 times, you will not learn it by heart so easily as if you read it 10 times, while attempting to recite it from time to time and consulting the text when your memory fails."
So I've happily been putting testing to more use with my students. Mostly, I'm using the opening and closing activities from Every Minute Counts, and the good news is that it's been very easy to do this in every class (both math and psych).
This is what it looks like right now:
Start of class: "put away notes and books and try your best to solve the problem on the board". Typically I'll have a basic problem that tests recall of previous lesson or homework. Sometimes I'll include another problem which opens up to whatever material we're doing the current lesson. As an example, last time with my Seniors, I started with the question "P(getting 2 sixes by tossing two dice once) = ?" and on the other half of the board had the question "P(getting two pink socks out of a drawer with 3 pink, 2 orange and 2 red) = ?" This led us straight into the distinction between dependent and independent events, and thus served two aims at once.
End of class: "list the main ideas from this lesson". After a few minutes they are allowed to compare their list with a classmate, and a minute or so later check their notes.
This has been incredibly easy. The main difficulty has been that students seem unused to, or unwilling, to let go of notes and book and classmate-support. I've spent a significant amount of minutes convincing them that this is a good idea, even if it feels frustrating to not remember everything you think you should. I'm usually strong at starting, weak at following up - so the fact that this is working and growing is a sign to me that this is worth pursuing and I hope that students will learn to test themselves while doing homework or revising as well.