Act responsibly. 'The buck stops with me,' said Willie Walsh, chief executive of British Airways, after Heathrow's Terminal 5 fiasco. With so many people willing to pass the buck, admitting a mistake makes a big impact.
Be specific. What are you apologising for - your behaviour, the consequences, or both? Build on 'I'm sorry I told the client she could have the proposal by tomorrow' with 'and I'm sorry this means you have to work late'. Showing that you understand both the mistake and the impact will make an apology ring true.
Rebuild trust. Explain what you'll do to avoid a repeat offence. Putting a plan in place will help people regain confidence in you.
Say it like you mean it. Russell Brand's response to the 'Sachsgate' fiasco was to say: 'I'd like to take this opportunity to issue a personal Russell Brand apology to Andrew Sachs ... for a message that Jonathan and I left on his answer phone. But it was quite funny.' Far from ameliorating a difficult situation, this 'apology' simply fed the fire.
Let it all out. We respond best when we see people's human side. Explain the emotions behind your mistake - 'I felt under pressure to hit targets' or 'I didn't want to let anyone down' - and you're more likely to gain people's understanding.
Make amends. Do whatever you can to compensate: restore the damage with an explanatory e-mail to a wronged client; help someone out by covering their 8am meeting; or try a treat, such as dinner for two. Actions speak louder than words.
Know when to hold back. If you're sure something's not your fault - perhaps you missed a deadline because of last-minute client requests - show empathy but be wary of shouldering the blame. Maintain credibility by replacing 'I'm sorry for ...' with 'I regret that ...'
The Mind Gym: Relationships is published by Little, Brown at £12.99 - www.themindgym.com/books