Working online as transcriber is not easy nor hard. I think it is good for people knows how to evaluate and can detect the critics immediately.When you doing transcribing you have to do it correctly.First you have to read their rules and guidelines before you take the test, failure to read will lead you to fail the test also. Second, you must do it accurately or do the job according to what they have asked for. Third, you must have a good English grammar so you can do the job easily. Without understanding the instructions and the nature of the job you are applying for, will lead into failure. I have tried to apply for transcribing but luckily, I even follow their everything and I know I have answered it correctly but not perfectly. Well, I guess it's not for everyone.
I think there is no technique of doing the job, just follow and understand the rules and guidelines.