Everyone has struggled during a test. Instead, it is because of not studying or a brain fart. While some struggle with finding ways to study, or are just too lazy, there are many easy and simple ways to get ready for a test.

Flash cards are an amazing way to start studying. You put a term on the front a definition on the back. You keep pulling the cards until you know them well. Keep shuffling the cards each time you finish the deck. Quiz yourself with the flashcards. I usually study flashcards until I get the deck completely right three times in a row.

Study with a friend. Studying with a friend benefits both sides of the party. You both learn the material better. You can quiz each other just like the flashcards. I would go until you reach an acknowledgment of the topic that is needed. You can always over-excel your standards too. You could also compete with your friends in study games.

Reread over previous classwork on the topic. Classwork and homework are always good to look over before a test. As they give you questions and answers related to the topic of learning. If you spend time on your work then it will be better to study for the tests. If you make a subpar effort on your class and homework then you will not be able to study well for the upcoming test.
Rereading the material is always beneficial. For any literature-based test, Science, English, and History, you can reread the material. Reading the material again gives you a re-established understanding of the topic. As it freshens the mind with the acknowledgment of the topic. Rereading the material finalizes your remembrance for the test on the topic of studying.
As there are multiple ways to study. I believe that flashcards are the best way to study. As you don’t have to read a bunch of pages especially if your test is on a long part of a book. You don’t need to rely on your past self to have good beneficial work. And if you don’t have any friends then you can’t study with them