Pick a topic that is presented in your textbook. When you are going through a textbook in class, you only briefly touch on the various subjects, so your term paper allows you to go more in-depth on topics. For example, if you are in a film class and briefly touched on how the long cut works, you can write a term paper that goes into more detail about why this type of cut it used and how it makes an impact on the film. Your textbook is full of ideas, so you don't have to be creative and think of them on your own.
Get creative with your topic and pick something that wasn't covered in class, but still pertains to your subject. For example, for a class about government, choose to write your paper on something that was not covered in class or only covered briefly. Since it was not specifically discussed in class, you should clear it with your teacher before beginning.
Some teachers give you a list of possible topics because they know coming up with one can be difficult. You can easily choose one of these that you think you would most enjoy writing about or you can use it as a guide and slightly modify the options that are given. Picking something that interests you is very important because it helps you engage more with the topic.
Incorporate some of your personal interests into your term paper. This gives you more education about the things you love and you have an interesting topic no one else will be writing about. Again, you need to clear this with your teacher as it may not have been directly addressed in your class. For example, in a class about astronomy, you might write about a space expedition that was not taught in class.