Plan out your time! Make a list of tasks, rather than subjects—this will allow you to be more focused on concrete actions rather than vague categories such as “study math.” What problems, in particular, are you going to focus on? What grammar will you review? The more specific you can get, the more you’ll be able to block out your study time and stay on task.
Creating smaller tasks is also a great way to write a paper! There are a lot of different steps involved for both analytical (brainstorming, collecting evidence, writing analysis, coming up with a thesis, outlining, building your paragraphs) and creative (brainstorming, free-writing, coming up with a narrative arc, etc.) writing—breaking down the writing process will make it more approachable and also give you time to draft and revise.
Build in time to review. Go through your notes from your classes and write down the main takeaways from the class. Be sure to note any questions you might have as you review.
Take breaks, but make sure you schedule them in and stick to your plan. This will keep you from procrastinating and also make your study time more effective.
A great study method is the Pomodoro Method, which builds in short breaks—it recommends 25 minutes of study with a short 5-minute break, and after 4 cycles a longer, 10-minute break. A simple, easy to use timer for the Pomodoro method can be found here (and as a bonus, it also allows you to input a to-do list!)
Eliminate distractions. Turn your phone off or leave it in a drawer. Close all the tabs on your computer unless they are directly related to what you’re studying. If you have a hard time getting distracted by social media, consider installing a website blocker such as Self Control that will keep you from visiting social media or streaming services. Once you turn it on, it cannot be turned off until the allotted time runs out.