There's no denying that sometimes money makes the perfect gift -- just ask your teenage family members. But much as we like to receive money, the sight of a stack of envelopes can be anticlimactic.
Instead of simply tucking cash into a greeting card, give careful consideration to its packaging: Perhaps it could masquerade as another gift, such as a CD, a favorite candy, or a wallet. Or you could throw recipients off the trail completely by concealing the bills in take-out containers that sport pretty bows, or in mysteriously tiny shopping bags hung as tree ornaments.
Your intention when giving currency or a gift certificate is to delight: You want your loved one to use it to buy (or save toward) something he or she really desires. When your present is a joy to behold, you convey this spirit, making it as personal and thoughtful as any other.