This oldie is a highly-regarded, very common system that makes it especially easier to retain information. By reviewing things as you go, you might even get away with less studying.
Divide your page into two columns. The left one (which could also just be the back of the previous page in your notebook) is narrower. You're going to jot larger ideas in this column: the 5-dollar-words and big bullet points. In the right column, you're going to take down as much information as possible. The right column is allowed to be messy, have pictures and tables—it's not necessarily organized. To some students, it's just regular notes. But as you go, record the main corresponding idea in the left column.
Every so often, cover the detailed notes on the right and just examine the main points and new vocab. See how much you can recite and explain in your own words. Then remove your hand and see how you did. Depending on the teacher, you might do this during lulls in the discussion or after class.
Some versions of the Cornell system leave the last few lines on each page for summarizing the whole page. Since what's on a given page doesn't necessarily group together nicely, I don't recommend doing it. But summarizing can help you with wading through piles of pages when studying time comes.