The first thing to remember when writing a college paper is that it needs to be focused. Nothing is more confusing to a reader than not being able to tell what your primary subject matter is because there are too many other ideas being discussed. While you may have many ideas about what you want to write your paper on, your professor only wants to hear one of them, so narrow down your topic choices to the one that you think you would best be able to develop. You want to make sure that the focus of your paper is not too broad, as you may have trouble fitting in too much information, but you also want to make sure that it is not too narrow, as you may not have enough information to fit into the paper.
The second thing you need to remember when writing a paper is that you are trying to create an argument. After clearly stating your thesis, it is your job to develop and defend it through supportive ideas and evidence. Your professor will not be grading you on the relevant information and details you were able to include in your paper, but on your ability to think critically and analytically about the subject. Before you sit down to begin writing your paper, be sure to ask yourself what the point is that you are trying to prove, and then figure out what evidence you have to do so. Be sure to build your argument based upon your strongest evidence, as the strength of it will determine the strength of your argument.
The third thing you need to remember when writing a paper is that it needs to be structured. You are trying to convince your audience, in this case your professor, that your interpretation of the material is valid. The best way to do this is through structuring your paper in such a way that best supports your argument. Create a clear outline for your paper to follow, and don't be afraid to change it as you see fit throughout the writing process. You also want your paper to be structured in such a way that progresses your argument, flows clearly from point to point, and is directed by your thesis. Once you think you have found an outline that best structures your paper, examine it to make sure it presents your argument in a logical, thorough, and thoughtful way.