Go over this checklist before recording your voiceover:
Practice reading your copy out loud Listen to your words. They should sound comfortable, conversational, even informal.
Avoid technical jargon That demands extra effort from your listeners, and you might lose them.
Short sentences work best If you find yourself stumbling over certain phrases, rewrite them.
Stress important words and phrases As you review your copy, underline important words. When you record your voiceover, you'll want to give those words extra emphasismore volume and punch.
Mark pauses Mark logical breaks in narration with short parallel lines.
Avoid overly smooth and constant pacing That's characteristic of a scripted delivery. You don't want to remind viewers that this is TV. It's real life. It's conversational.
Punch up your voice Do not slip into a dull, monotone voice. Instead, add some zest and enthusiasm to your narration.
Practice Record a couple of narrations and listen. Most first-time narrators mumble or swallow words. Have you made yourself clear?
Don't pop your Ps and Ts As you say P- and T-words, you project a small blast of wind. Avoid speaking directly into the mic.
Wear a headset It'll help you avoid popping Ps or speaking with too much sibilancean overemphasis on the S sound. And it'll help you minimize room noise and other extraneous sounds.