You may have had teachers who advised you against using mnemonic "devices." One of my teachers called them "vices" and equated using them to cheating. He was the type who believed that, because he had learned to do things the hard way, so should we! A much more reasonable view is that today's students need to know every trick they can in order to cope with the ever-expanding world of knowledge. You can use mnemonics as a recall cue to intervene between a question on an exam and your knowledge of the answer.
A brief introduction to some mnemonic techniques is given in Appendix I. Skill in using them will serve you well not only in college but throughout your life. I therefore urge you to practice using them at every opportunity.