Replacing standard pre-wedding celebrations with a Jack and Jill party, in which both members of the wedding party and friends from each side attend, offers a twist for those who do not want a standard celebration. Jack and Jill parties are often more like a casual social gathering or a party, than a standard wedding shower, and can be anything from a brunch or dinner in style at a fine restaurant to a casual potluck at home.

Determine who will be on the planning committee. The maid of honor typically throws a bridal shower, while the best man plans the bachelor party, but this is not a standard party. Since both wedding members are involved, planning and input should be shared by bridesmaids, groomsmen and even the couple's parents to reflect both the bride and groom.

Discuss what type of celebration would best suit the couple. Perhaps they would feel happiest at a relaxed backyard barbecue with beer, or maybe they would love an elegant brunch. How closely the celebration reflects the couple will determine its success.

Instruct the bride and groom to register for household gifts. Like a typical shower, many guests will want to bring a gift. For a Jack and Jill party, both people should have a say on the registry, since the celebration is for both of them.

Plan the entertainment so it coincides with the theme of the party. A simple, backyard barbecue needs no more than a well-thought out play-list, where a larger, more extensive event might require a DJ. Contact caterers or restaurants well in advance. If you plan on holding a potluck, decide on a central theme so guests will have an idea of what to bring, even if the theme is as general as brunch or Mexican food.

Send out invitations at least three to four weeks early. This is particularly important if the couple is registering for gifts; people need time to not only make arrangements to attend, free their schedules and commit, but they need time to purchase a gift. Include information on the type of food you will serve, requests for what the guests can bring, whether or not children are welcome and if alcohol is being served.

Enjoy the party. A benefit of Jack and Jill parties is they do not adhere to the rigid format of bridal showers, with structured games or a specific limit on who is allowed to attend. Jack and Jill parties provide a chance to casually relax with friends, meet new people from the bride or groom's side and celebrate before the big day.