Keep a vocabulary log on hand whenever you read the newspaper, magazines or books. Each time you come across a new word, or a new word for a concept you are already familiar, write down the word. Refer to a thesaurus or a dictionary to define the word and identify synonyms to record in your log.
Practice building sentences. After each new entry, leave enough room to write out a sentence in which you use the new vocabulary word to establish a context for the entry. If you find multiple synonyms, try to write one sentence that could be applied to each of the words for that main entry. Say the sentences aloud to pronounce the word correctly.
Set a weekly goal. Add to your log a specific amount of words each week, perhaps three or four the first week. One way to help keep count is to add the date range to each new entry. Try to plan at least one activity a week in which you engage someone in conversation and use all of the vocabulary words you learned in that week.
Write, blog, participate in online forums and chats, and expose yourself to as many medians of communication as possible. Do not be afraid to introduce new words to your friends. When someone asks you what a word means, take advantage of the opportunity because educating others will reinforce the knowledge in your mind.