Members of newly blended families spend a fair amount of time deciding when to stay out of each other’s way. That’s tough to do during the holidays.

“The early years of being a stepfamily are the toughest,” says Maggie Scarf, author of “The Remarriage Blueprint: How Remarried Couples and Their Families Succeed or Fail” (Scribner). “You’re still getting to know each other.”

Getting to know each other, of course, requires devoting some time to each other’s interests and pursuits. Which can leave parents wondering: Do we insist the stepsiblings attend each other’s holiday recitals? How about the Christmas open house at Aunt Millie’s, who wasn’t, technically, their aunt last Christmas? Is it antisocial to let half of the gang skip that ice skating social?

“Now, biological siblings aren’t always excited about attending one another’s events,” says family therapist Ron Deal, author of “The Smart Stepfamily: Seven Steps to a Healthy Family” (Bethany House Publishers). “A lot of older brothers don’t want to go to their younger sister’s Thanksgiving production. That’s an important perspective to keep.”

And just as individual nuclear families have to decide how and when to enforce dutiful attendance (excitement optional), blended families have to negotiate and create their own rituals and requirements. We gathered some advice from the experts.

Choose your battles

“Seek balance when you’re insisting that kids be involved in activities they’re not really excited about,” Deal says. “If there are five activities on the calendar, it’s perfectly OK to insist everyone goes to three and cut them a break on the other two. There’s nothing wrong with compartmentalizing family members.”

Family unity is one thing. Family unity at all costs is quite another.

“If you get the idea that there’s strong opposition, that the child is going to come and sulk and be furious and make other people miserable, I would really think in advance about whether it’s worth it,” Scarf says. “I would make my preference clear: ‘This is what we’d really like you to do with us today.’ But saying you absolutely have to all show up as a happy family unit is just going to create some bad, bad memories.”

Also, be strategic about what you prioritize.

“Do you all have to go to every soccer game? No,” says psychologist Edward Farber, founder of the Virginia-based Reston Family Center, which provides family counseling. “Does everyone go to the champion soccer game? Yes. Does a stepbrother have to show up at his stepsister’s big piano recital? Yes. Does he have to watch every activity she does? No.”

Play in private

“Why do you have to bond over a soccer game anyway?” Farber says. “There are so many other creative, meaningful ways to bond.”

(Ways that don’t involve the watchful eyes of your friends and relatives and neighbors. Bonus!)

“Before you worry about looking like one big, happy family, everyone should be spending a lot of one-on-one time together,” Scarf says. “The biological parent with each biological child. The stepparent with each stepchild. The stepchildren with each other. That should be happening before the holidays and during the holidays.”

Stepsiblings who have learned how to make each other laugh (and how to push each other’s buttons) are going to have a lot more invested in the performances and activities they do end up attending.

Which is why you should continue to extend invitations to all family members, regardless of how many times other invitations have been rejected.

“Nothing you do in child development is one-time,” says Farber. “Your child doesn’t like broccoli the first time? You come back with it again later. Same principle.”

Create new rituals

If the kids aren’t excited about attending each other’s activities, and they’re divided about whether to uphold the holdover traditions, it may be time to start some new ones.

“Write a new history of traditions,” Farber says. “Don’t try to re-create the first marriage. That one didn’t work.

“Help them incorporate their old lives while they accept the new life,” he continues. “One kid goes to a soccer game, while one kid goes to a piano recital, but we all hike together on Saturdays.”

Fresh traditions are imperative, Deal says, to cement the blended family. “Fostering new family rituals is a principle for building a healthy stepfamily. You’re building new rituals, which over time helps create a sense of family identity.”

Leave plenty of room for emotions, some happy, some not so happy

“All of this has to be tempered by the fact that we’re not forcing love and we’re not demanding affection,” Deal says. “When children feel pressure from a parent figure to love one another and feel affection for one another like biological siblings, it tends to create more resistance.

“You can ask them to go and support their stepbrother at his holiday concert, but do so with the expectation that they might not love being there. And that’s OK.”

You can do your best to enforce civil behavior, Farber says, but the rest has to come from their hearts.

“Just because the parent decided to marry someone else doesn’t mean the children have to be best friends,” he says. “They have to be respectful and they have to follow the same rules of the household. But they don’t have to be buddies.”

Above all, give every member plenty of space to feel whatever it is they’re feeling.

“Even if the new marriage is infinitely happier than the last one, the kids have suffered a loss of their first family,” Scarf says. “You can’t force everyone to have a wonderful time. Be ready for big, loaded, intense feelings and, as the parents, take the attitude of, ‘I’m learning about you. Thank you for teaching me.’”