Specifically: "When I worked at Lulu, Bob Young used to say that whenever you screw up, it's actually a tremendous opportunity to win a customer's loyalty by making it right."
Pretend the topic is a bug found or any customer job delayed/flubbed. This is a great piece of advice. Generally engineering-types focus very much on explaining what happened and not enough time on hearing the customer, apologizing, and explaining that it won't happen again. It's our natural personality as problem solvers.
But I've seen how apologizing for even a major mistake can win loyalty, get help fixing the problem, and even make deals bigger/longer. "Wait, that problem happened because we are sending the data to you in that convoluted way? We should either fix that or work together on how to make it easier for you to support it." If done right, the relationship will become more collaborative (your ultimate goal) and the customer will appreciate you more.