Remember the time your mom let your cousin have an extra swing at your birthday piñata and he was the one who broke it instead of you? Three decades later and your parents still joke about the hissy fit you threw. Parties can bring out the worst in the guest of honor, a sibling or even a well-meaning parent. We consulted the experts for advice on dealing with common birthday meltdowns.

Party anxiety Some children aren’t comfortable being the center of attention, and might dive under the nearest table before blowing out the candles or opening presents. “There’s so much stimulation that all prep can go out the window,” says psychologist Andy Seltzer. “The important thing is how you respond—the goal is to comfort your child.” For instance, ask your tot if he wants you to help him blow out the candles—or if he’d like a relative or friend to do the honors.

Sibling rivalry With all the focus on the birthday child, brothers and sisters can feel left out. “It doesn’t come naturally for kids to be happy for their sibling,” says Lisa Spiegel, cofounder of Soho Parenting. “For kids two-and-a-half and older, talk to them about what will happen at the party and be very clear about your expectations for them.” You can also give siblings a special job during the festivities, as photographer, door greeter or favor distributor, suggests Janeen Hayward, a counselor with parenting consultants Swellbeing. It can help to have grandparents or a babysitter on hand to keep an eye on siblings.

The gimmes With all the gifts, goody bags and general excess of city birthday parties, how can you raise grateful tots? “Birthdays are an opportunity for children to learn to consider other people’s feelings,” says Spiegel. “Remind kids before the party to say thank-you—even if the gift is something they already have.” And while you don’t need to declare “No gifts, please” on the invite, you can encourage guests to bring a book/take a book, or set a dollar limit. A new website, ECHOage.com, allows you to send an e-mail invitation requesting a small monetary donation in lieu of a gift, half of which goes to charity, while the other half goes toward one larger gift for the birthday child.

Invitation diplomacy If you haven’t invited every classmate to the party, prepare your child to be sensitive to other kids’ feelings at school. Spiegel recommends reminding your tot that kids who weren’t invited might feel bad not to be included, but says you shouldn’t ask your child to lie or keep his birthday plans a secret. “It’s an important life lesson that we don’t get invited to everything. It’s part of growing up.”