If you are working hard enough, practicing actively will be a good choice. Sit down, open a newspaper and your MicroSoft Word (or any text editor), try to type the word from newspaper one by one. At first it may be hard and full of typo, but if you consist the practice regularly, like 1 hour everyday, eventually you will get a obvious improvement. Typing Eagle also provides a free and handy online typing test for practicing. You could utilize the tool to practice and compare your progress with others easily.
2. Practice passively
For people who don't have sufficient time and effort to practice actively, I suggest them to practice it "passively". Live yourself in a world with typing - start typing in your game's chatroom, instant messagener and search engine! You don't have to be a fast typist, you just need to keep using your typing skill in a daily basis. Most of the teens get their typing skills from online game's chatroom. It is an efficient and time saving way to improve your typing skill.
3. Familiar with your keyboard
Many people neglect the importance of keyboard, which actually highly affects your typing speed. A good keyboard provides fast response speed when you click on a single keycap. Begineers are recommanded to use a keyboard with clear key label on each keycap. Everybody may prefer different size and layout for his keyboard. Find your right one could help you to get a higher WPM. If the keyboard doesn't suit you, don't be guilty to change a new one.