Jeffrey Hedquist has some good tips in the January issue for making voices sound more conversational. Here are a couple of others:
If someone is projecting or using their ‘announcer voice’ when they should be natural, I’ll walk into the booth on some pretext... to adjust the mic or talk about the copy. While we’re talking one-on-one, I’ll ask them to get a physical fix on what it feels like in their throat, and go for the same feeling while reading... sometimes, that’s all it takes.
If they don’t have a good kinesthetic sense or still don’t seem to be getting it, I’ll draw a big smiley face on the copy, and tell them to talk to the face. They’ll laugh - which is good in itself - but it changes their focus and can do wonders.
A good variation on this, when working with children, is to keep a small stuffed animal around for them to talk to. I use a Steiff tiger about 6" long: its four legs are just the right shape to clamp onto a short shotgun without blocking the mic’s slots. I use the directional mic instead of a cardioid with children to get more distance, which lets them move a little in their chair without changing the sound. Since the tiger is soft and padded, it doesn’t reflect into the mic. And with very small children, I let them play with the tiger while we’re still in the control room... that way, they can take a ‘friend’ with them into the booth.
Clio/Emmy-winning sound design