"The thing that companies and individuals need most, they often get least – and that's the truth." So says Mindy Mackenzie, a former marriage counsellor who earned the nickname of "the Velvet Hammer" while driving major changes at liquor giant Beam, Inc.

Now a McKinsey senior advisor, she has written a book, The Courage Solution: The Power of Truth Telling with Your Boss, Peers, and Team. It's full of chatty but practical advice on how to tell the truth ... in a way that is most likely to be heard and less likely to get you fired.