Not all noise can be tackled in this way, though: you need to listen for clicks, plosives, digital glitches and the like. These can normally be acceptably repaired by using a 'heal' tool, or a pencil tool to redraw the waveform. Popped 'p's can often be 'fixed' using a high‑pass filter set at 100Hz. For a single glitch, you can zoom in and cut out the cycle of the waveform in which the glitch appears. Just be careful to start and end the cut where the waveform crosses the centre line, otherwise you'll inadvertently add another digital glitch. If glitches are frequent, it's likely that there's a problem with your audio interface's buffer settings — it may be just a playback issue.
One of the most important rules is to ensure you value yourself as a professional. If you undervalue your own service it can be hard to later charge for the correct rates. A professional voice-over should cost a minimum amount, even if you’re new. If you allow clients to low-ball your work from the outset it will continue to set the expectation that they can get a voiceover from you on the cheap. This can then mean the difference between making a living and paying bills or not.
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.