When you try to put a new idea into your own words, you're elaborating.
"The more you can explain about the way your new learning relates to prior knowledge," the authors write, "the stronger your grasp of the new learning will be, and the more connections you create that will help you remember it later."
For instance, if you're in physics class and trying to understand heat transfer, try to tie the concept into your real-life experiences, say, by imagining how a warm cup of coffee disperses heat into your hands.