It might be the holiday season, or your best client's birthday or corporate anniversary. You would like to honor the occasion and thank clients for their business, but the challenge often lies in picking out the perfect gift.

"It shouldn't be too personal, too extravagant or too impersonal," said Anne Lardner, public relations manager for the Promotional Products Association International. "It can be a simple gift, but it has to fit the interest of the recipient. While the buyer determines the cost of the product, it's the client who determines the value."

In some cases, cost is constrained by the corporation itself.

Jacqueline Whitmore, author of "Business Class: Etiquette Essentials for Success at Work," said a company might not allow their employees to accept gifts, or allow them to accept them up to a certain price, and a call to its human resources or purchasing department will tell you the policy. The policies are typically designed to prevent people from trying to curry favor with the company.

It's usually not a problem with small businesses, added Leah Ingram, author of "Gifts Anytime," it but could be an issue with Fortune 500 companies. If that's the case, Ingram recommended writing a letter thanking the client for its business.

If you've determined you're in the clear, the next step is figuring out what to buy.

Whitmore recommends purchasing gifts that match an individual's interest. If the person is a sports fan, give tickets to see a favorite team. For theater lovers choose tickets to a play.

Another option is gift cards, such as those to a bookstore for an avid reader or for iTunes for a music fan.

While determining the gift card value may be tricky, your corporation's policy might set the limit. Ingram cautions that the Internal Revenue Service only allows a deduction of $25 per person per year.

However, the amount of work the client provides also might be a determining factor. "If a client brings in $10,000 worth of work, a $25 gift card is going to look awfully stingy," Ingram said.

Another thing to keep in mind is whether your clients know one another, Whitmore said. Giving a Waterford vase to one and a tin of cookies to another might not be the best idea.

Other options are gifts that are indigenous to an area, such as Key lime cookies from a Florida business or handmade items.

Gift givers might want to make a donation to a charity in the recipient's name, Ingram said. Taking time to figure out what charity resonates is crucial. An animal lover might appreciate a donation to the Humane Society.

Another option is to send a gift that an individual or a department can share.

"Nobody is offended by food," Ingram said. "Even somebody on Weight Watchers can share."

It could be a gift basket filled with coffees and teas or a box of truffles. Whitmore even suggested having pizza delivered.

Businesses might also consider sending promotional products, such as desk accessories, golf items, candies or fruits. With 750,000 promotional products available, the choices run the gamut.

But Lardner cautioned that the gift giver's name should be subtly imprinted. She also recommended that companies pay close attention to their gift packaging. The right packaging "really elevates a mundane gift to something really memorable."

Gift givers also need to keep in mind the diversity of today's workplace, both in terms of culture and views. A "holiday" gift may be more appropriate than a "Christmas" gift.

If you're doing business abroad, Whitmore suggested checking out executiveplanet.com for business customs in various countries.