Here is good videos about it:
Keep your camera less than 6 feet from your subject for on-board audio.
When you do not have professional gear at your disposal, one of the most important tips I can offer is to keep the camera close to your subject. People often forget that audio is half of video. People will tolerate bad video quality, but they will not watch a video they cannot hear. Think about a boot-leg movie you've watched; maybe the picture wasn't great, but you continued watching. However, if you couldn't hear what the actors were saying, you'd stop it right away; there'd be no reason to watch.
Place the camera near the window and have your subject face the light.
There's a good chance many of your interviews will take place indoors. Hopefully you can conduct those interviews when it is light outside. Darkness is the enemy of video. This tip is all about utilizing windows. Leveraging natural light is all about knowing where to place your subject. Intuition might say to put your subject near the window; but that's only half correct. The key is to have your camera very near the window and have your subject face the light. *If you are outdoors, I suggest shooting in the shade.*
Overhead lights cast unwanted shadows on your subjects face.
Not all lights are created equal. Given that we don't have large professional lighting kits to illuminate our subjects, it's important we understand what light we do have available. While intuition might tell you to turn on all the lights in the room, this is not a great idea; unless of course it's dark outside or there are no windows available.
Resist the urge to comment while your subject is speaking.
When you are interviewing a person you often want to make them feel comfortable and engage in normal conversation, but conducting an interview is not exactly normal. If your voice interrupts your subject you might ruin a great audio bite for your project. It's important to keep your mouth closed while they are speaking. Maintain eye contact and use body language to let them know what that are saying is helpful to you and you are engaged.
Have your subject state the question in their answer.
This tip is a little more advanced and only after you've spent some time editing interviews will it make complete sense. The idea is that if you ask the subject to repeat the question in their answer, the answer will make sense as a stand-alone video clip. Without the subject stating the question, and without audio of the interviewer asking the question - those viewing the video may not understand the answer being given.
As the video instructs, if you ask someone what their favorite color is, you are begging for a one-word answer. A simple way to get a more elaborate answer is to add 'and-why' to the question: “What is your favorite color, and why?”. This elicits a more detailed, and often more useful, answer.
Using a close-up is engaging and provides the best audio fidelity.
Cinematographers know all about these three types of shots: Wide, Medium, and Close (Close-up) and how to use them as story-telling devices. For the purposes of low budget interviewing however, we must remember to get good audio; so we are really limited to medium and close-up shots unless we have multiple cameras.
Utilizing the rule-of-thirds makes your shots more interesting.
We are all used to taking pictures on our phones these days - and usually we just center our subjects and shoot. However, professional photographers and videographers often use the rule-of-thirds to create more interesting compositions. The rule-of-thirds simple states that if you divide your scene into 9 equal boxes using two vertical lines and two horizontal lines; you should place your subject at the intersection of a pair of lines.