I have developed my own technique that has worked well for my children and myself. I ask myself after reading a chapter, doing homework or learning new information the following questions. What have I learned? How does this help me? What do I do with this new knowledge? The result is that by thinking about what I have learned I understand it better and it becomes lodged in my memory. I basically make the new information part of my thinking and observing life. When you think how can I use or apply this new information it becomes part of your working knowledge and is not easily forgotten. I have tried many of the other ways of memorizing but have found that if you come to learning with a joy and a willingness to immerse oneself you don't have to work that hard. Always asking questions puts your mind in a state to learn and remember. I hope that this is helpful.
This is what works for me too. My ability to recall information from material I consume took a big hit after years of reading things online that can be forgotten inconsequentially, with no direct implications in real life and no post-reading discussion with peers or teachers such as in a school or academic environment.
What I found is that without a direct challenge to your understanding after reading something, be it through formalised tests, questions or social competition, you forget to learn. Your attention and learning mechanisms become defective.
Asking yourself a few simple questions about what you just read and how it is useful or important to you helps a lot.
Funnily enough, I think this may be accidently done by parents for their kids learning improvement. When they get home at a young age parents, or atleast mine, would ask what I learned in school. My memory from times I answered faithfully vs started answering "nothing" seems to be rooted deeper. Could simply be due to age though.
I think this is a version of what I do via blogging. When I learn something new, writing a blog post about it tends to help it stick better as well as exposing and clarifying remaining misunderstandings.