We all know that we are living in a world where there are no more boundaries regarding information and so it is just normal that the physical distances won't stop that labor from getting from one place to the other. I suppose you have heard it many times that some people are working for companies that can be found in another country or on another continent and it is very likely that they have never seen in person their employer. Most probably these people get their jobs through a video interview.
There are some tips that you should know about in case you are preparing for a video interview. I think advance planning is the most important. (The first thing might be to send the company or the recruiter every material that he or she might need, like your resume or portfolio.) The most important thing that you need to send to the company or the recruiter is your resume or portfolio. You should also think about arriving early so that you will have time to get situated. In case you aren't familiar with the equipment, you should ask for assistance. You might do this even though you are familiar with it, just to be sure.
It is always a big question what clothes to choose for the interview. In this case the rules are about the same as in case of a traditional interview; the golden rule is to dress professionally. There is no need for special pieces, you should wear the same thing as you would at a person-to-person interview. There were some people who were wearing a dress shirt, jacket and tie, thinking that the bottom half won't be seen, but at a moment they got up and the interviewer got a look of their jeans. This is a mistake you should avoid making and don't think about the fact that the interviewer won't see.
You should make sure that the table you have the interview at, is neat and clean so that there will be nothing to distract the interviewer. Regarding the equipment you should know that the microphone picks up every noise, so avoid tapping a pen or shuffling pages. Although you will be speaking to monitor, so to say, you should still try to make eye contact by looking at the camera. It is also important to see how you are looking and so it might be useful to have two windows, in one of them seeing yourself.
The process of the interview itself is just like in case of any other interview, since the objective of the interviewer doesn't change. You will have to answer the same type of questions but you should be prepared to ask questions as well. If you have some doubts regarding the process of the interview, it is quite okay to ask questions about how you are doing, and you should remember that the interviewers are people as well.
These are some very useful video interview tips that you should keep in mind in case you will have to participate at such an interview sometime in the future.