How to make a rom-com love potion

Richard Gere and Julia Roberts. Diane Keaton and Woody Allen. Meg Ryan and Tom Hanks.

To that list of repeat on-screen romantics, add Adam Sandler and Drew Barrymore.

Barrymore and Sandler are three-peating their rom-com streak with Blended, opening Friday. It's more adult than their other two capers The Wedding Singer and 50 First Dates, dealing this time with emotionally charred single parents who wind up on vacation together.

But there's still the Barrymore goofiness, and the Sandler sweetness, particularly in scenes with his daughters.

"Going into the third one, we had a built-in nostalgia," says director Frank Coraci. "You root for them to be together. They have such a deep friendship and respect for each other. In this movie, they make fun of each other. There's always a sweetness when they get together."

From the start, Sandler, through his Happy Madison production company, has written parts for his friends, and hired his buddies to work on his films; Coraci, who met Sandler when both were students at NYU, has directed The Wedding Singer, The Waterboy, Click and Blended.

Sandler, a star so famous he's his own brand at this point, says that simply put, "I'm more comfortable hanging out with my buddies. I trust them. They make me laugh the most. I'm very at ease with my friends, and that's why I tend to want to do it again and again with my friends."

Plus, says Barrymore, they have similar sensibilities when it comes to movies, and want to make stuff that kids can see with their parents. "We love funny but we like romantic and sweetness and goodness and a lack of crassness," she says.

Coraci says Sandler and Barrymore have been tight since Singer, shot when both were single. "Now they both have two daughters each. It allowed them to draw from real parenthood," he says.

The other keys to making on-screen love work, over and over and over:

1. Hire actors who have the right comic timing and can go toe to toe. "It's rare when you have two people who are funny in a rom-com, and that's one of the benefits with Adam and Drew," says Coraci.

2. And make sure they can actually act, while also having chemistry and a sense of authenticity when they do hook up, without that ick factor. "It's having two people who are funny together but are able to be romantic, and that's a unique thing to have," says Coraci.

3. Deliver on the premise of the film. If it's a family flick, don't overdo the gross-out humor – or downer plotlines. "We earn the trust of the audience that we won't be schmaltzy or clichéd," says Coraci.

4. Work with people you admire, respect and know very well, to have a comfort level that lets you be loose. "When you show up to work at a new job, you're trying to do what you love, it's more comfortable to be around people, you're less inhibited – you have the support of people around you who know you," says Coraci. "I've known Adam for so long. When we did Click, his dad had just died. He was able to really let go in that movie."

5. Allow your actors to play to their strengths and interests. Blended, for example, spoke to what occupies Sandler and Barrymore now: playgrounds, playdates and bedtimes. Life with daughters Sadie, 8, and Sunny, 5, says Sandler, is "different, no doubt about it. You do wake up knowing you're going to (be with) them. You're going to have a good day that's about them."