1) Have a reason for learning a language. That goal could be anything: to read a book, chat with a family member, pass a gen. ed. course, make a certain recipe, etc. If you establish an objective, you’ll be more motivated and see greater success. I started taking French to fill an elective and decided to major in French because I wanted to achieve bilingualism. Now, I learn other languages (Spanish, eventually German and maybe Arabic) to read documents that will help me understand French/Francophone culture.
2) Change the language on your phone. I keep my PC in English au cas où I need to take it to a help desk, but my phone and iPod are in French. Just by changing one setting, I get to practice French without trying. The technology vocab reinforces itself every time I démarre une conversation or open mon calendrier.
3) Listen to music, podcasts, radio, anything in the language while doing mindless tasks (like creating a works cited page) just to have the sounds in your brain. I suggest watching a lyric video when you start listening to new songs, to make sure you hear the correct words and make sense of the song. Petit à petit, you’ll recognize lyrics in songs you hear for the first time.
4) These tips apply to learning any language! I strengthened my French skills as I refreshed my Spanish, and my experience learning French facilitated my success in Spanish class. Likewise, by learning some romance languages, I improved my English. So plurilinguism can benefit anyone, not just Humanities students.