I had trouble studying the way I "should" so I worked to find ways that got me learning the material for myself. If you like surfing the web, think of questions about the material and surf the web learning as you go and finding things that keep your interest. If you can swamp your mind, live and breathe the material in an interesting way, enough of it will stick so you will be able to do fine on the test, even figure out stuff you didn't know you could figure out.

If you like to read, read fiction and biography about the time and people and try to get yourself in that mindset, as if you are one of them. Then studying the material you will be able to follow along better and it will be more interesting to you because you will know what it means to the original discoverers. It's much more interesting studying physics, for example, knowing the story of the apple hitting Newton's head but even more interesting knowing what he was doing under the tree and what else was going on in his life. The people whose principles we study had lives like ours, problems like ours, etc. and putting ourselves in their shoes helps me and has the added benefit of taking my mind off my own problems of the moment.