Be a Tutor         

If you have a good understanding of one subject, you can find a job as a tutor.Try go to your local youth center. Many youth centers pay tutors for math, English, History and Science in their after-school programs.

If you'd like,ask your counselor at school if they pay tutors for after-school programs at your school.

Also, you can advertise on your own and once you get a following the word of mouth referrals will start coming in quickly. You should dvertise your offer in places where parents will see the advertisement. The parents are your clients.

There are number of websites available who allow you to become a tutor by hiring you, or you can become a private tutor which is often more rewarding. There are also many websites who provide their platform for free of cost.

If you are really good at art and computers, Second Life allows you to earn money by selling designs for people's places, houses, and avatars. check out some sites for more info.

You should find out how much others are charging for tuition and charge similar rates. Charging too little or too much will make you seem outside of the competitive pool, and therefore hinder your ability to find work.