What I found worked for me in Legal Studies was to learn to understand the content so that I knew why things were the way they were. That way I never really forgot anything and I had applicable knowledge at my disposal when a question was asking me about something.
And although it's a little different, I did a semester of Economics in Uni and got a HD for it and I took the same approach. It's more about understanding than memory when it comes to social sciences, I have found.