Try to visualize the topic and the purpose of learning. Scan important points and examples. Write them in your own words for better understanding and learning.
After you’ve read a topic or major section of the topic, close your book and recall the main ideas and points. Give yourself time to understand the basics of the concepts. Don’t try to re-read multiple times without understanding.
When dealing with a difficult chapter, don’t think that you need to cram or require long study hours to complete it at one go. Study daily for some time instead of a marathon study session on a single day.
Always test through revision or self-quizzing to reflect your learning at the end of the day. Continuously revise tough topics (10-15 mins will be fine) even when you are studying another topic.
Learn the basics first and then advance. According to Marcus Geduld (a teacher for 20+ years), “Anyone can learn Calculus IF they’ve first learned the stuff leaning up to it. Some people make the mistake of jumping straight to Calculus without first learning basic arithmetic.
If you’re less interested in the subject you are studying, then first complete easier chapters and solve problems from them to gain the confidence for learning the difficult chapters.
Have patience. Difficult topics and chapters take more concentration and effort than easier topics.
When you are making your study schedule, give more time to difficult topics. How much time do you need to give to difficult topics? For that, you should consult a teacher.