Honestly, the best methods I know for studying are

1. Set a specific, dedicated space and time free of distractions which will be repeatable. This makes it a habit.
2. Don't just read and try to memorise. To actually understand the material, writing it out or explaining it to another person with no knowledge of the subject seems to work best for a lot of people. You won't remember it rote, but having multiple ways of explaining the concept works really well. I have learned more by teaching than by studying, 100%
3. TALK TO YOUR TEACHER AFTER CLASS! Seriously, even if you're not having an issue, make use of those office hours, you'll wish you had if you skip it. We're there to help you, and we want you to learn and succeed. We'd much rather have a student that really needs and comes to us for help rather than one that usually knows what they're doing but doesn't approach when they stumble. Professor office hours aren't just an unrealistic porn plot, they're a great way to learn the material better than you would otherwise, even just by having it explained a different way.
4. Take breaks. 15 minutes every hour is good, but you can flex that up or down depending on your needs and how focused you are that day. When you take a break, I recommend not just fucking around on the internet. If you're able to, do some exercise or go for a walk!

Joke answer that's kinda not a joke. Clear your mind by getting off about 15-20 mins before you study. Ace people, you probably already have a clear head, otherwise do some meditation or something that helps you clear your mind and calm yourself physically. Seriously, it actually helps to sort of get out any sort of wiggles or distractions and helps you really take in the material. Plus it makes studying more fun.