There's both an art and a science to gift giving, according to UC Davis consumer psychologist Margaret Rucker

Rucker, a professor of textiles and clothing, has studied gift-giving trends for more than 15 years as an example of social "exchange theory." Intending to improve the gift-giving process by providing a better understanding of the traditions of various groups, Rucker has examined gift exchanges among gay men, between the sexes and across different cultures.

Although gift-giving traditions vary from group to group, Rucker offers a few basic suggestions for gift givers.

A gift should match the desires of the recipient, not the giver. It should be expensive only in comparison to the giver's budget and it should represent a commitment to the relationship.

While men tend to look at gift giving more as an economic exchange of goods, women take a more personal and romantic approach. For women, an extraordinarily thoughtful gesture may be more appreciated than an expensive object.

"When a partner climbed to the top of a tree to get a robin's egg, that was a good gift for one woman," Rucker said.

She advises gift givers to steer clear of gag gifts, practical gifts, generic items, additions to collections, and objects that represent both low cost and little effort. Gifts that symbolize something the giver wants the recipient to become -- exercise machines and a year's supply of diet shakes -- will definitely not be appreciated, she warns.