You messed up. Maybe you made your spouse cry, forgot your kid's basketball game, got caught in a lie — or worse. Take a hint from Justin Beiber's hit new single, "Sorry" — an apology is definitely in order. So … what should you say?

Our apologies are usually "woefully inadequate because we have a fundamental misunderstanding about their purpose," said Guy Winch, psychologist and author of "Emotional First Aid." "Most apologies tend to be excuses or justifications that neglect to address the feelings of the person to whom we're apologizing."

Before you start to craft your apology, you need to remember the goal is to make the other person feel better, not yourself.

"We will only feel better, and less guilty, if they feel better and forgive us," Winch said.

Sincerity will be at the root of any good apology, said Toni Coleman, a psychotherapist and relationship coach based in McLean, Va. "Too often apologies are delivered with a 'but' in an attempt at justification or rationalization," she said.

As in, "But it was just one time." "But I had a miserable day at work." "But I didn't think."

The moment you ask for forgiveness isn't the time to make excuses, said Jonathan Alpert, psychotherapist and author of "Be Fearless: Change Your Life in 28 Days." That's when you should show true remorse, Coleman said. You also should listen to your loved ones explain how you've hurt them.

"If apologies are an art form, most of us can barely finger-paint," Winch said. Admitting fallibility might be the first hurdle for many on the path to a good apology, but even those willing to own up to their mistakes should learn some techniques for how to do it effectively.

Winch said the ideal apology will include five specific ingredients:

1. An "I'm sorry" statement.

2. Expression of regret for your mistake.

3. An acknowledgment that social norms or relationship expectations were violated.

4. A statement of empathy in which you acknowledge how your actions may have hurt the other person.

5. A request for forgiveness.

According to Winch, No. 3 — acknowledging why the act was wrong — "tends to sensitize the offender to the issue and reduce the likelihood of offending in this way again."

That's why it's so important to make it clear to the person you harmed that you understand why your decision was a poor one. Did you violate their trust? Break a promise? Act selfishly? Say that.

But there is a risk in going overboard, Alpert warned. Keep the apology concise and avoid saying too much or straying from the point, which could "dilute your intended message," he said.

Even if your apology includes all the necessary parts, it needs to feel as if it has a heart, too.

"Don't be afraid to show genuine emotion," Alpert said. "This will go a long way in humanizing you and showing sincerity, both of which are critical in winning back trust and respect."

Choose your timing

The trickier aspect of apologizing is identifying the best time to do it.

Good apologies require reflection and thought, so rushing one might make it less effective, Winch warned.

"Apologies that come too quickly can feel insincere," because they seem more a knee-jerk reaction than deliberate recognition of your mistakes, he said.

For Alpert, the timing all depends on the circumstances. Waiting a few hours or days (whatever feels appropriate based on the offense) to give the person you wronged time to calm down could play to your advantage.

"Initially after a wrongdoing, the person might be fuming with anger, hatred even, and they'll be highly defensive," Alpert said. "Waiting for them to cool down will help ensure that your apology is better accepted."

And even if you've left a wound open for a while, he insisted, "a late apology is better than no apology."

That said, even if you offer the most detailed, earnest apology, understand that the person you wronged may not be ready — now or ever — to forgive.

If your apology is rejected, "go back to the drawing board" and try again, Winch advised. Be even more sincere next time. Don't be afraid to feel vulnerable.

"When people feel understood, when they feel you truly 'got' how your actions impacted them, they are far more likely to offer true forgiveness," Winch said.

And if all else fails: "Ask the person what you can do to try to make things better," Alpert said.