Revision techniques

When revising I feel like I’m just constantly memorising information which takes a really long time, I can never really understand what I’m learning
Does anyone have any revision tips for actually understanding what I’m learning?
And also tips for retaining information- I feel like I memorise something for a test then completely forget

What subjects do you do? For my bio and chem then I will draw things out and look at how a bunch of different textbooks describe the same thing until I find one that helps me to understand. Then write everything onto flashcards on anki to keep it in my head, but if you're stuck on something English-y or history-y then I have no advice sorry. Good luck!