Move around. I don’t mean dance while you’re studying, but rather change locations. One day study your spelling words in the living room, another day perhaps sitting on the porch. It appears that this change of scene helps the brain form multiple associations or triggers, with the information, causing it to become better anchored.
Mix it up. Instead of focusing intently on memorizing verb forms in Spanish or multiplication tables in math for an hour, spend the hour studying different facets of the same subject. So maybe 20 minutes on the memorizing of verb forms, another 20 practicing speaking, and then 20 doing some reading. In math, do mixed problem sets, work on word problems, and memorize facts. This helps force the brain to pick up on similarities and differences, which is how it will encounter information in the real world.
Test yourself. Studies have shown that self tests help you to refocus on specifics and slows down forgetting. When you ‘miss’ an answer you have to go back and revisit the material reinforcing it in your brain.
Space it out. While you can get by by ‘cramming’ for a test, the information is quickly lost. Multiple studies have shown that studying the material, getting a night’s sleep, restudying the material, and then even reviewing it again two days later, makes for more of the information being retained. It’s sort of like layering a cake. Who among you wouldn’t agree that a three layer cake is much better than a single layer one?
It would seem that for most students, whether they're in elementary school or post graduate school, the phrase, “Variety is the spice of life,” seems to show results in the realm of study and retention.