Testing effect

Frequent Low-Stakes Quizzes and Testing To Enhance Learning and Student Metacognition
According to Oswego, University of New York:"Student learning is enhanced by frequent practice, and this is most effective when the practice is distributed across time and across tasks."Low-stakes simply means that there is no grade attached to whatever test you set up. The only thing students need to trade is their time and energy.

This, in turn, removes any extrinsic reward making room for intrinsic motivations.

Again, if psychological safety is high enough, students can compare how they learned for these low-stakes tests, how much time they spent, etc. to enhance student metacognition even further.