It's only after this sort of processing that I'll start cleaning up the recording and dealing with the gaps of silence between spoken passages. A noise gate (or an off‑line 'strip‑silence' function) can be used to automatically mute sections that fall below a certain level. However, if not used carefully, these tools will clip the 'T's and 'P's off the ends of words, and shut out natural breathing sounds. Worse, if your recording is noisy, a noise gate will actually draw attention to the problem, since your client will be able to hear the difference between room tone and absolute muting. Another trick is to use a downward expander to reduce the noise floor of quiet sections, rather than cut out the noise completely.
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.
If a client likes your demo, they may invite you to audition. In the 21st century, you can download the audition script, record the audition at home, and then send the results to your client over the Internet. Prepare yourself for a life of constant auditions: Even successful voice pros may do many more auditions than actual jobs. But if enough jobs come your way, it's worth it.
The advice we present here is tried, tested, and true. Peter Dickson is the foremost leading professional voice actor in the UK known for voicing the X-Factor, Britain’s Got Talent, Live at the Apollo, The London 2012 Olympic Games and countless brand commercials. In a stellar  career spanning 40 years, he has worked on over 120 TV shows and series, many of them award winning, been a promo voice on 60 TV and Radio channels around the world, been a featured voice actor on 30 AAA game titles, and voiced in excess of 30,000 radio and TV commercials!
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.
In late 2009, my wife Simone received an email from Prague in the Czech Republic. The sender, Mirek Jirku, was heading up a project to record voice messages for the foreign‑language versions of the latest Avast! anti‑virus software. Mirek sent us eight messages to be recorded, specified the fee and deadline, and requested a slow, friendly read. He asked us to send separate stereo MP3 files (at 160kbps or higher quality) for each message, specified that we'd have to sign a non‑disclosure agreement before recording, that we'd need to invoice afterwards, and that he'd pay via a wire transfer instead of PayPal (which is often used for international payments).
You need to appreciate that there is a lot to learn and do before your first paid voice acting job. Yes, you want to get out there and start auditioning. But first, you’re going to need proper training, equipment, resources, and yes, some natural talent. The great news is that even though the voice over industry is competitive, there is plenty of voice over work out there for everyone. This guide on how to become a voice actor will give you a good idea of where to start. 

As editor, you need to turn the raw recording into the final version of the file you'll be sending to your client. Editing during a recording session can be problematic, and particularly so if you're recording in a domestic environment. How can you expect to hear the drone of the dishwasher ruining your recording if the dishwasher is still running as you edit? I'll look in more detail at setting up a voiceover recording studio next time, but for now, if recording in a separate room or isolated booth isn't an option, at least try to edit the file the following morning (or maybe at night) when there's less noise around — because hearing your recording with a fresh ear and in a quieter environment will help you to make better editing decisions, and will reveal noises that slipped your attention earlier.