Reading and listening are excellent ways to learn new vocabulary but they can also help you learn more about a subject if you ask yourself questions afterward.
Check your knowledge
When you read or listen to something interesting it is natural to want to find out more. To start with, write down what you learned from the material. Next, write three questions that you want to know the answer to but the material did not answer.
Research
Type your questions into Google or another search engine or look at the English books in your local library. Read or listen to materials that might help you. Take notes of new information and new vocabulary.
Put it all together
When you finish your research, write down everything you learned and how it all links together.
This can be a long project but if it is interesting you will stay motivated. Good luck!