I realise I spend a lot of time studying, but that I'm not very aware of how I study, so this is mostly a collection of my thoughts, in no particular order, on trying to study effectively. - Reading is never sufficient, I need to take notes, solve problems, and be exposed to a concept multiple times in order to remember it. - More so, I need to see concepts and tools in a variety of ways to gain any meaningful understanding of it. This is why problems, applications, and examples are important, as well as seeing the same concept explored by different sources and authors. - Remembering facts and definitions, as they are presented, is arduous compared to understanding why we have them in the first place, and how they behave. Again, this is why examples and problems are important. I don't believe that you can meaningfully understand something from just the definition. - If you can, talk to others about what you're studying. This is much easier if you're a student taking a class than if you want to learn about a topic by yourself, although there are online forums for people learning about almost any topic imaginable. This again exposes you to new viewpoints and perspectives.
Furthermore, think about how you would explain what you are studying to a layperson, without having to put them through an hour long lecture in the topic. - Ask stupid questions, even if you just ask yourself. If you don't know the answer immediately, and you think you should, then find out. Not knowing is only going to make your life harder. - Answer questions from other students. Again, online forums and stack exchange sites are great for this if you aren't in a class. Being able to help others means that you understand what makes a topic difficult or confusing to learn, and can make you aware of difficulties that you didn't notice in the first place. - Distinguish between studying hard, and studying effectively. You need to balance reinforcing the material you already know, and encountering new material for the first time. I have no clue as to what the best mix between these two is, or should be. NB: For context, I study mathematics, and some of this may not transfer effectively to your choice of subject.