Think about getting your school pictures taken (I know, I know, terrible memories of braces. If you are in a darker room, or you are getting on video chat in the evening, find a lamp that you can plugin and place about a foot in front of your laptop to give you some good lighting.
Also, wireless internet signal can fade in and out.
If you have an ethernet cable handy (they usually come free with your internet router or you can purchase one on Amazon for less than $10), plug it in to ensure you have a steady connection.
People will forgive your video quality, but they won’t forgive your sound.
If the person on the other end can’t understand what you are saying, you’re in trouble!
If you are taking your video interview using a laptop or tablet, charging it to 100% is a great idea.