Giving of your time and talents to another person is one of the best decisions you can make. In doing so, you're sharing a part of you with someone else in an effort to help in some way. Volunteering is just one of the ways that you can become a part of this process and spread yourself in the new place where you live. Help doesn't need to just be something that you do locally; you can volunteer abroad too.
Another way to volunteer while you are abroad is to give your time as an English language teacher. If you have good grammar and fair teaching skills, you can be a tremendous asset to those that need to learn English. You might want to volunteer as a tutor with a single student or teach an entire class in the afternoons. You can also help tutor people over the internet though web-based classes or simply advertise your services as an editor or assistant for those already in English classes.
You might also want to volunteer abroad to teach others about a particular valuable skill that you have. For example, if you're well-versed in computers, you might be able to teach someone about the basics of computer repair. If your hobby is digital photography, you might want to pass this skill along. When you have something that you can teach, chances are good that someone else will want to learn about it - see what people need and how you can provide a service.
Volunteering can also be about working for charities and relief organizations as needed or on a continuous basis. There are numerous chapters of the Red Cross, for example, that are always looking for new people to help. You might also want to work at local charity organizations that area focused on your particular area. And in doing so, you can begin to see what other needs you may be able to fulfill.