Write down unfamiliar words and look them up in a dictionary later or online for a definition. Consider using flash cards. You can write down the word on one side and the definition on the other. Then quiz yourself periodically.
Keep a handy notebook where you can jot down the new words you hear along with the definitions. Also, write down their Latin roots and pay attention to suffixes and prefixes. This can help you remember them.
Take some time to review the new words when you have time. Make up sentences using unfamiliar words, and write them down.
Try to guess the meaning of unfamiliar words before you look them up in a dictionary. By studying the Latin roots of words, it becomes easier to guess the meaning of a word.
Read books and magazine articles in your spare time. The more reading you do, the better your vocabulary will be.
Use the new words you learn in conversation.