What are some good studying/learning techniques?

I'm a college freshmen, and I am really motivated to do well and not only be prepared to enter the work force on my feet, but stretch my brain in ways i never thought possible. I have never been able to pinpoint how I learn best, and my studying habits are very inefficient. The only things that keep my grades above water are just the sheer amount of time i spend studying. What are some good study techniques to learn an idea and make it my own?