Christmas cards should always be handwritten in ink. It is customary for the husband's name to be given before his wife's, but this is a matter of personal choice.
The wife's forename is, however, retained. Therefore, a card should be inscribed from 'John and Mary Smith', rather than from 'Mr and Mrs John Smith'.
If Christmas cards are pre-printed, then the surname should be crossed through for recipients on first-name terms with the senders.
It is permissible to include a short personal letter when the card is to friends or relatives who are rarely seen. However, a general round-robin newsletter, or photographs of the family and pets, are not considered acceptable inclusions.
It is often wise to take care when sending cards to those of other faiths: to this end 'season's greetings' can be a more appropriate a greeting.
Christmas cards are a traditional expression of seasonal goodwill and the sending of cards should be in this spirit, rather than as a means of self-promotion.
Christmas cards are traditionally sent in envelopes with diagonal flaps. Always use stamps on Christmas cards (preferably with a seasonal theme) - putting your personal cards through the office franking machine looks careless.