Etiquette of signing your greeting card:

The form most often used for a personalized card is:

Mr. and Mrs. John Jones
Mary and John Jones

(The woman’s name appears first so that the first and last name of
John Jones remains intact and is not separated)

The  children’s names should be separated from the parents’ names
and appear in the second line in order of seniority regardless of sex:

Mary and John Jones
and George
Mary and John Jones
George, Sally and Johnnie

Other acceptable forms are:
The John Charles Joneses
Mary, John
and George Jones
The Joneses
Mary, John and George

Most names form the plural by adding “s”. 
Exceptions are names ending in the sounds s, sh, ch, x or z
which form the plural by adding “es”.
Examples: The John Hartses, Walshes, Welches, Fixes, Heinzes.
When this appears awkward, we suggest using the word “Family” as

The John Jones Family

Names too long to fit on one line should be divided into two lines:

Millicent and Desmond
Van Landingham

When titles are used, many can be spelled out:

Reverend and Mrs. Paul Carlson
Doctor and Mrs. Paul Carlson
Dr. and Mrs. Paul Carlson

A widow may use her husband’s first name:

Mrs. Paul Carlson
Mrs. Sheila Carlson
Sheila Carlson