When you finish doing the homework for a given section, it is a good idea to review the previous section covered, a section earlier in the same chapter and maybe one in an earlier chapter. Pick one randomly or one that seems similar to what you are doing now. Read back over the old sections and notes and think about the concepts and examples. Then work a few problems from each part of the old homework set to convince yourself that you can still do it. Think about how the old sections relate to or lead into the new one.
Many students find it useful to make flash cards for each definition or principle in a section.
On one side write the name of the concept, on the other the concept itself and an example. These cards can help you learn concepts well for an exam. This idea won't appeal to everyone, but consider giving it a try. Consider inviting a couple of people from class to meet with you at the Student Center, the library, a restaurant or someone's home for a few hours of study. Work on your homework problems separately for a while and then stop and compare and discuss answers.