I have some tips for you:
1. Read Read Read more.
Most vocabulary words are learned from context. The more words you're exposed to, the better vocabulary you will have. While you read, pay close attention to words you don't know. First, try to figure out their meanings from context. Then look the words up. Read and listen to challenging material so that you'll be exposed to many new words.
2. Learn vocabulary everyday.
Don't learn to many words a day. You may forget them tomorrow. You should learn 1-5 words a day and learn everyday.
3. Learn vocabulary by watching or listening English movies, musics
When you watch a movie, try to learn how native speakers use words. You just copy the way that words are used.
4. Buy a good dictionary
A good dictionary will help you to understand clearly about new words
5. Play with words. Play Scrabble, Boggle, and do crossword puzzles
6. Use flash cards
Flash cards can turn any “down time” into study time. If you're standing in line, waiting for a movie to start, or sitting in a waiting room, whip out your cards and expand your vocabulary.
7. Play words games
8. Take vocabulary tests
