Important: Use headphones to check the audio quality of your test recording. Your computer speakers will not be good enough for this. Headphones allow you to listen closely to ensure clear audio. Obviously, you want the audio to sound good on even the cheapest speaker, but you will be much happier if you use headphones. Remember, a good portion of your video viewers will listen this way, so you want to be sure they’ll have an optimal experience.
Because I've prepared properly, the first take is often the one I end up editing and sending to my client. The second is simply there as a safety net, in case I need to replace any mistakes while editing. It's much better to capture such drop‑ins during the same session as the main performance, as you can be sure that the mic will be in the same place and your voice will have a similar character in both takes.
The quality of your voice over depends almost entirely o the skill of the voice actor you use. A good voice actor will have perfect enunciation (ie, be very easy to understand), speak at an ideal pace (not too fast and not too slow), and have a pleasing voice. They should also be good at acting, and able to convey the feeling or emotions required by the script, using vocal variance and tone to keep the words interesting while also embodying the desired mood. 

Your own voice is your most important piece of equipment. If you're new to the voice-acting world, look around to see if there are classes or coaching in your area. Outside of class, practice speaking clearly and confidently. Learn to do this even with material you've never seen before. It's also important to learn voice care – straining or injuring your voice can hurt you and your career.
Part of great voice over work is ensuring that you pronounce each word correctly and that you speak clearly enough to be understood. Avoid mumbling but don’t shout or over-enunciate, either. Don’t worry, though. No one expects you to sound like a professional voice actor. The best thing you can do is speak naturally and clearly and the rest will follow in time.
Recording voice overs like a pro isn’t that difficult when you know how to do it. You may have noticed that the actual recording part plays little part when compared to the preparation. Taking the proper steps before you hit the record button and then taking the time to edit your audio appropriately will go a long way to ensuring your voice overs sound professional and engaging.
Before you get down to the nitty-gritty, though, I recommend doing a test recording to ensure your equipment works properly and your audio levels are strong. You don’t need to record the entire script, but a few paragraphs will give you enough to ensure that the audio is clear, at an appropriate level, and doesn’t include any stray or ambient noises.
The clarity of your voice and a comfortable volume may be the most essential parts of great audio. If your voice over recording is fuzzy or muddy sounding, it will be difficult for people to understand. Audiences likely will be distracted and unable to absorb the information or may simply move on. Either way, they miss your message and you miss an opportunity to share what your knowledge.

Also listen for sibilance. Strong 'ess' sounds are best corrected at source, by using good mic technique, but sometimes they're unavoidable. If you hear an 'ess' that really sizzles in your recording, you can manually reduce its volume. You can, of course, also use a de‑esser, but do be careful, as applying some de‑essers to the entire audio file can alter the sound of your recording. It often works best to apply them to short sections, either offline or using automation. My preferred de‑esser plug‑in is the one sold by Eiosis (,Make sure you record some silence at the end of each take. That way, if a great performance suffers from noise issues, you have something to feed your noise‑reduction processors. Just don't rely on this technique too much! which cleverly separates the esses from the rest of the audio and allows you to manipulate them independently. If you want to learn about some more advanced strategies for de‑essing check out Mike Senior's article from SOS May 2009 (/sos/may09/articles/deessing.htm).

One of my favorite things about being a voice-over actor is the incredibly supportive community. Use your community to communicate with other voice-over actors regarding rates and best business practices. I have rarely found anyone who is secretive or not willing to share their past experiences. By being a generous and communicative community, we are stronger as voice actors and can advocate for ourselves to get paid appropriately. If you are operating from a home studio and all communication is between yourself and the client (versus an agent as the intermediary) it’s usually your responsibility to invoice after sending your VO files. I always include a polite 30-day payment term at the bottom of my invoice. In certain states (for example, New York) there is a “Freelancing isn’t Free Act”, in which you can politely mention to be paid in a timely manner.