The most important thing to keep in mind when trying to improve your voiceover performance is that you must keep your voice in good health. From the moment you approach the microphone, your throat, tongue, and mouth should be in harmonious, healthy unison - like a Nashville star ready to rock a show.
One of the best ways to achieve this is through proper hydration - dry mouth can ruin any voiceover read through, so make sure to drink water throughout the day before your gig.
If you forget and start downing a bunch of water right before you get to the job, you could be forced to take multiple trips to the bathroom which can waste not only time - but money (especially if you have an engineer standing by). As a rule of thumb, you should avoid cold drinks - warm/hot tea and room temperature water will produce the best results.
Whatever you do, stay hydrated and make sure your throat is clear (use an expectorant or cough suppressant if necessary). But avoid anything with antihistamines since they will dry you out.
Just as you wouldn’t take off on a marathon without stretching your legs, it’s unwise to go into a recording session without preparing your voice. One clever trick is doing some tongue twisters leading up to your session - repeatedly try these phrases in low octaves, your normal voice, and finally a high pitch.
Don’t push too hard though - remember this is just a warmup; stretch (not stress) your vocal cords. We recommend standing while you perform this exercise, as standing posture expands your diaphragm and helps you prepare to project the best version of your voice. You should literally massage your face... your cheeks, forehead and lips. "Buzz" your lips to loosen them up.
Once you’re sufficiently warmed up, take some practice runs through your script using different tones - sad, mad, over the top - this will help you get a feel for what works best, and may give you fresh ideas if you’re stuck on a certain style for your script.
After you’ve familiarized yourself with the script, try doing a run through from memory. The best way to come across like you’re talking to someone rather than reading to them is to actually not be reading. Sounding authentic and believable is one of the hardest things to learn as a voiceover actor, and as such should be a top priority for your practice sessions and warmups.
Don’t be afraid of the competition - embrace them. One of the best ways to gain insights on how to improve your voiceovers is through listening closely to people who are successful in their voice careers.
Investigate how they got the jobs they have - that you feel you would want. Is there something they are doing better from which you can gain valuable lessons? Compare your own style with theirs, and carefully analyze the discrepancies with as little of your ego as possible.
Keep at it and don’t give up - patience, self-discipline, and hard work go a long way in this competitive industry!