Sally's parents are divorced but neither has re_married and are both hosting the wedding: Use the format above or if they prefer it, list Sally's mother's name on the first line and her father's on the second. Sally's parents have both remarried and are jointly hosting the wedding. Sally may wish to break with tradition and mention her step parents in which case Sally's mother and her husband's names should be on the first line with her father and his new wife's name on the second. Neither of Sally's parents is living: The invitation should be issued by whichever family member is hosting the wedding or by the couple themselves.
Think about the shape and size of your invitations in comparison with the style of wedding you are having. Formal weddings typically use a rectangular card for a more traditional look. However, if your wedding more on the playful side, think about going circular, scalloped, or even a square wedding invitation. Keep in mind, the bigger the envelope the more costly the postage.