There’s a craft in directing a voice-over, the one to avoid at all costs is where the producer/copywriter reads the script the way they think it should be read, in that situation I think it best that the voice-over and producer swap places straight away.
I have witnessed some classic bits of direction over the years, one was where a voice-over was asked to “put a bit of top spin” on the next take….new balls please!
Another was “that was great, but could you do one more take, and this time be a bit more seductive on the word bank”…..yeah, look where that got us?
Now, call me old fashioned but I think that if you have a well crafted script and have given some thought to the casting of your voice-over, you won’t need to direct at all… at all.