Nice list of tips for greeting card writers on website "Greeting Card Writing" by Sandra Miller-Louden. Here's a sample.
TYPES OF GREETING CARDS:
TRADITIONAL: Traditional cards are those using rhymed, metered verse. The number of lines in the verse is generally divisible by four. Traditional verse is often done by a company’s in-house staff; although freelance work in this area has increased over the past several years.
CONTEMPORARY PROSE: Sometimes called “conversational prose” or “soft social expression,” these cards sound as if someone is talking. The voice is soft, gentle and realistic. Non-rhyming, it can be a phrase, single sentence or as long as 32-40 lines. Freelance work is actively sought for contemporary prose.
STUDIO OR HUMOROUS: These cards reflect current trends, foibles, frustrations and shared experiences. They are either written in a snappy, cutting edge style or in a cute, pun-filled voice. Humor is always needed from today’s freelance writers and it is, by far, the most popular type of greeting card on the racks today. Almost every company includes in its lines some kind of humorous offering.
ALTERNATE: The alternate card uses both contemporary prose and humor to get its message across. These cards carry themes such as coping, single parenting, surviving chemo, job loss, terminal illness, pet-sitting thank you, death of a pet, etc. Alternate cards are very fluid, expanding with the times and events of the nation and world surrounding us. Freelance contributions are actively solicited here as well.
.....more tips continued