For a double-scoop of fun at your child's next birthday, why not host a dual party? Combined parties for siblings, cousins, or friends with close birthdays are a growing trend, says Marnie Ann Pacino, author and illustrator of\u00a0Cool Party, Mom! The Other Three Words Every Mother Loves to Hear. With kids' parties becoming bigger, grander affairs, double parties let moms share the workload and the expense of birthday festivities. Birthday parties are a much bigger deal than they used to be, says Pacino. "Between decorations, invites, favors, activities, and food, it can be exhausting and expensive. Who wouldn't love some help running errands, cleaning up and footing the bill?" And double parties don't just benefit parents. For kids, a combined party often means a bigger party with more guests. "A potato sack race with 20 kids is bound to produce more giggles than the same race with ten kids!" notes Pacino. Shared parties are also convenient for invitees' parents. Kathleen Yarbro combined birthday parties for Lilly, 3, and Chloe, 1, into one celebration because the girls' birthdays are 10 days apart\u2014one party was less hassle for everyone involved. "Most of the families we'd invite were the same for both girls," she says. "It made more sense to invite them all at once, instead of asking them to come over two weekends in a row." Think a double-decker party might work for your family? Here's how to host a sweet soiree that your child (or children) will cherish for years. Get Input The first step to a successful double party: Ask the kids involved if it's what they want (if kids are too young to ask, it's probably a safe bet that they don't mind sharing the spotlight). Parents shouldn't assume that all kids necessarily want a combined party. And some children with very different temperaments\u2014one who's high strung, and another who's more retiring, for example\u2014may not make compatible party-mates. If the guests of honor are on board, give both kids equal say in planning decisions. Theme Scheme If the birthday kids can't agree on a theme, don't choose\u2014let each child pick a theme, and use both. When Christy Ramersrus hosted a double party for her two children, Joslyn, 7, chose a pony theme, while Carson, 4, picked Thomas The Tank Engine. Instead of deciding between the two themes, the family had separate decorations and a cake for each child in different rooms of the house. The theme combination was eclectic, Ramersrus admits, but the arrangement kept her kids happy and their guests entertained. Gift Guidelines Buying double the birthday gifts can cause sticker shock for some guests. To ensure that people aren't disinclined from attending because of the burden of purchasing two gifts, consider specifying simple gifts, or setting a no-gift policy. Book exchanges, where each guest brings a book to exchange in lieu of a gift, are a popular way to skirt the gift issue. Solo Spotlight Even at a combined party, kids should still feel special at their birthday shindig. Two birthday cakes are a must, as well as taking turns being first during games and activities. At the Yarbro party, each girl got their own rendition of the "Happy Birthday" song and sat in a seat of honor to open gifts. Double parties can be a blast, but they're not for everyone, Pacino notes. Sibling rivalry can be intense during certain times in a child's development\u2014do parents want to put up with more sibling bickering during what's supposed to be a fun event? Solo birthday parties also give kids in large families a rare chance to be the center of attention. But for many kids, double parties mean double the fun. So set a budget, set realistic expectations, get both birthday kids involved in planning, and get ready for a double-dose of frosting-fueled birthday memories.