Imagine yourself stranded on a desert island. All you have on hand is a piece of charcoal, a sliver of birch bark and a pop bottle that has washed up on shore. If you're going to get rescued, you'd better get a message out fast. You'll need to be clear, concise – and perhaps a little dramatic, too. You'd do well to choose your words carefully because this could be your only chance.

Think of your company's tagline as that critical note in the bottle – the magic phrase embodies the essence of your mission, promise – of what makes you unique. The message that you deliver has got to be on target. If it's ambiguous, confusing, or too clever by half, your business risks being left high and dry for good.

Of course, you're an entrepreneur, not a castaway. Your venture is doing quite well, thank you – and you've managed to survive without a slogan so far. Do you really need one?

Yes, you do, says Shirley Lichti, founding partner of Marketing Magic and the co-author of Marketing – particularly if you operate a small business in a competitive environment. The right tagline gives your enterprise presence, authority and distinction. It's an anchor; it resonates with your internal stakeholders and customers and sticks to their brains like a catchy pop song. It sums up your brand and highlights your promise in bright yellow. But it's got to be good – and short. Here are some considerations.

Communicate One Key Message

There are different approaches for getting that vital idea across, says Paula Peters, author of The Ultimate Marketing Toolkit. But at the end of the day, that idea should be as singular as possible. You might look for a line that stresses a specific benefit that makes your company special. Bounty used this tactic when it came up with "The Quicker Picker-Upper." Or you might seek a slogan that clearly and explicitly describes your product or service, leaving absolutely no question about what it is you offer. No one, for example, can doubt what NyQuil does: it's "The night-time sniffling sneezing coughing aching stuffy head fever so you can rest medicine." The point is to isolate the principal element that makes your business unique. What differentiates you from the pack? Try to capture that concept in as few words as possible. Play with the phrasing until it has the ring of conviction and you're well on your way to producing a winning tagline.

Move People to Act

Sprite, the soft drink company, used this technique to great effect with its line "Obey Your Thirst." The slogan managed to parch the throats of its target consumers while at the same time urging them to quench that thirst with the company's product. Not bad for a mere three words. It's short, emotive, has personality and emphasizes Sprite's key promise – to quench thirst. AT&T also applied this method to bump up use of its long distance service. "Reach out and touch someone" evoked the kind of sentiment and emotion that motivated scores of folks to grab their telephones to call Grandma in Peoria. The message for you? Suppose you own a store that sells yoga clothing. You could call your customers to action with a line like "Find Your Sublime."

Seek to Inspire

When Apple came up with the line "The power to be your best," it delivered a challenge to its consumers and made its product a partner in that challenge. The trick here, says Shirley Lichti, is to create a tagline that not only inspires, it also reflects the personality of your brand. She cites "Think Different," another Apple tagline, as an example. "It makes a statement about the company as well as the type of person who buys its products," she says. "Many Apple consumers pride themselves on being people who are a little more discriminating than most." If you have a photography store, for instance, a line such as "Picture the Possibilities" might spark the response you're after.

A Sticky Line is a Good Line

The more memorable your slogan, the better it is. Avis got plenty of mileage out of its tagline, "We Try Harder," because it was virtually impossible to forget. "You're in good hands with Allstate" also gloms on to consumers' brains and stays put. "Most people instantly recognize and associate the word ‘When you care enough to send the very best' with Hallmark Cards," says Lichti. "Created 60 years ago, it has become one of the most enduring taglines in advertising history." Try to determine the single lasting attribute you'd like your customers to associate with your business and see if you can develop a tagline based on that concept.

Be Original, But Be Clear

Everyone wants to be inventive – but you shouldn't sacrifice clarity in the process. The financial organization, HSBC, managed to combine clarity and imagination with its tagline "The World's Local Bank." Stay away from vague or overused words or phrases, such as "innovative" or "the customer comes first." They do nothing to differentiate your product or describe what it is you offer. There's an art to producing a great tagline, certainly. But the effort is worth it. A tagline enhances your advertising and your image, serving as quick shorthand that helps potential clients identify and relate to your business. So we suggest you Just Do It, if you'll pardon the expression.