You can try studying in a closed room with air conditioner.Always try to understand the topic and you will be able to learn faster(at least it works for me!).If u feel sleepy u may drink tea or coffee or even take a break for 15-20 minutes............maybe it helps!
Ok! I know it sounds completely weird, but what I do is jump on a trampoline (if u have one), and read my study guide and or text book and or test resources. Also what I do us just right before I go to bed, i look over a few questions, read them, and solve them. And finally, I also have either me or my parents make me a list of questions that may/may not be on the test. Then, I answer them. I hope this helped!!!
When I study, I usually look over the questions AND answers. Then, I go away for at least 15 minutes, and come back and try to remember all of the answers. I continue this process, except each time going away for longer periods of time, and then trying to remember the answers. This way of studying has been very effective for me, and I hope it helps! :)