Five Tips on Studying Vocabulary:
1. Consider using an audio or computer resource to embed vocabulary more deeply into your memory. Learning to speak and hear German may not be necessary for reading German, but hearing and speaking it, will help you remember it better. See Audio Resources and Computer Interactive Software
2. Use flashcards. You can likely access the flashcards you need at flashcardexchange.com because someone has probably already entered them for you there. If you get a $20 lifetime subscription at flashcardexchange.com you can download and print out flashcards for the site. The website has a huge database of cards that were entered by participants in the site. For example, all of the vocabulay words for German Quickly and German for Reading Knowledge have been entered. You can do online quizzing there for free without buying any subscription. On that site, search the tag "quickly" for all of the German Quickly flashcards or search for "German Quickly" with the title search.
3. Walk. It is possible to walk and study vocabulary. This keeps you awake and helps you get some exercise. Checklist: flashcards (printed out from internet), rubber bands for holding flashcards (available at a drug store or Walmart or Amazon.com), a pen for notes.
4. Peer pressure. There is no substitute for the external pressure of having cumulative quizzes in a classroom with other students and a professor. See Courses in North America
5. Persist. See Tips on Motivation
What else have you found helpful for learning vocabulary?