Perhaps there is a hobby that both of you love to do. You can use this 'theme' in your wedding invitations as well. If you both love to fish, you could use fishing line and lures for your invitations, or a hobby of wood_working could provide you with a way to expand your hobby into creating some special invitations. Regardless, if there is a hobby that the two of you share that helps to define you as a couple, don't be afraid to use it to your advantage and choose the best part of your hobby to direct your unique wedding invitation choices.
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.