I love the SQ4R method for written material:

Survey - Scan the material to get the flow of how it is presented

Question - Scan the material again and develop questions you’d like to find the answers to

Read - self explanatory

Recite - read aloud

Review - Scan the material again and see if you can answer your original questions

and the most important…..

Reward - do something you enjoy to recharge your batteries or rest your brain

Another incredible paradigm shift that massively increases retention is to imagine that you are going to teach the material to someone else the following day. It really helps you to remember details.