Try writing things down as you go. It helps you study later on, anyway.

Read each paragraph and write down the purpose of that paragraph. For example, "Mosquitoes bite people and can spread diseases. The CDC warns us that mosquitoes are dangerous. They can spread malaria and other diseases. Mosquitoes are dangerous, and mosquito bites can itch like any other bug bite."

You would simply write, "CDC warns us that mosquitoes can spread malaria and other diseases." You don't need to write down that mosquitoes make itchy bites. That's useless information.

Then when you go back to studying for exams, you'll have a pretty good "cheat sheet."

Once you're done with all of that, make a more condensed cheat sheet. Remove any redundant information or combine sentences of yours to make things shorter.

The trick is, though... Try not to memorize anything unless it's dictionary words. Instead, focus on understanding what the material is about. If you understand it, then you don't really need to study all that hard, because there's nothing to "memorize." At least that's my experience.