Listening to lectures is a good start. I found that listening to it at 2-3x speed multiple times works best for me. Skimmimg a variety of articles on the topic, this helps for understanding the jargon used in the field. Jargon intimatedes me when I'm reading for a thorough understanding. So if I already have a flavor of the field it becomes much easier to grasp what is written. The best method yet is just spending time with people who know a lot about that field.