Self-explanation has been found to be effective by cognitive scientists. It can be done in your head or an actual explanation you give out loud, to an audience. You can do it in pairs in class or by yourself studying at home.  To explain something you have to pull together the relevant knowledge, put it in the right sequence and connect it up so that the idea you’re explaining makes sense.  This strengthens connections you’ve made and flushes out areas you’re still not sure of.