Download Skype for free on your computer. Skype is a program that allows you to make international calls free of charge and gives you and your student a "live on-screen" picture of each other. This is a distinct advantage because the student often needs to see how the mouth and tongue move in order to make certain English sounds.Face-to-face conversations are also important, as they often facilitate meaning more easily. When your student is perplexed, you can see that and quickly resolve the problem.
Decide if you want to work for a language company. Online language teaching is very competitive, so earnings may start low but will increase over time. There are advantages to working for a company. Teaching materials are chosen and purchased for your use, providing you with a framework in which to work. There are no legality issues with the materials and you save a lot of time in preparation. In addition, the company will advertise on the web with its own website, allowing you to focus on what you do best---teach. Lastly, tracking billing and payments, keeping make-up lessons straight, and writing up contracts---all record keeping administrative tasks---are done for you.
Think about how well you can split your focus and time. If you are comfortable being both teacher and company administrator, then set up up your website and link to language employment sites. Write up very specific agreements for clients, spelling out rates, make-up policy and the length of the course. Keep in mind that materials used must be copyright legal.
Research professional materials for yourself. Whether you teach for a language company or decide to teach for yourself, you will need to buy excellent resource materials geared toward online English teaching. There are several books out that offer superb language games, writing exercises and activities designed for many different learning styles. Engaging your students in numerous ways of learning benefits both you as a teacher and your students as learners.