Faced with a little free time on her hands during a trip to Los Angeles, Carrie Underwood had a decision to make. "It was go shopping or go write with these two," she says gesturing to Chris DeStefano and Ashley Gorley (pictured above with Carrie). "I think I made the right decision."

Choosing songwriting over shopping indeed proved to be the right move that day as the trio penned Carrie's No. 1 hit "Good Girl," the first single from her current album Blown Away.

Carrie, Ashley and Chris were honored with a No. 1 party on Tuesday afternoon (Aug. 28) in Nashville at the Country Music Association's offices. "Good Girl" is Carrie's 15th No. 1 song, and the Oklahoma born entertainer was a co-writer on seven of those hits. It was the very first No. 1 for Chris, who divides his time between LA and Nashville, and it was the eighth No. 1 for Ashley, whose other chart-toppers include Carrie's "All American Girl," Darius Rucker's "It Won't Be Like This for Long," Trace Adkins' "You're Gonna Miss This" and Brad Paisley's "Then" and "American Saturday Night."

"I actually crashed Chris and Ashley's writing session," Carrie says of how their collaboration that day happened. "They were writing in LA and I had a day off. I said 'Can I come?' So I showed up and they kind of had this groove going, because Chris DeStefano is like a little mad scientist. He has this giant setup in his apartment that is all Pro Tools and he can play just about any instrument you can think of, so by the end of a couple hours there we had a demo in our hands to walk out with."

Though it was one of the last songs she wrote, it became the album's first single. "When you think of a first single from a new album, I like the thought of having something uptempo and fun because I go sing it everywhere," Carrie says. "I thought it would be a great one to kick everything off with because it's just fun [for] spring and summertime and it's a lot of fun to sing. People can sing along and have fun with it."

Carrie says she took a different approach in writing for the Blown Away album. "I wanted to switch up my writing style because I felt like I would block off a month or two to go and write," she explains. "Most of my good songs were at the beginning of it when I was super excited and going in to write. I have a short attention span so this time we really broke everything up. I'd go write for a week then I'd go do something else, then I'd come back and write for a few days then go do something else. That definitely produced better results cause it was always new. I didn't get into a routine writing."

Over the course of writing for her four albums, Carrie's confidence has grown. "I definitely feel more comfortable in my role as a writer," she admits, "and lucky enough to write with some really amazing people that I learn something new from every time I'm in the room with them."

Carrie's current single, "Blown Away," is at No. 12 this week on Billboard's Hot Country Songs chart and climbing. "The first time I heard 'Blown Away' I just loved it so much because it was different than anything I'd heard before and that was really attractive to me," Carrie says of the Josh Kear/Chris Tompkins penned tune. "No matter how many albums I make, I want them to all sound different, be different and have different kinds of songs on them. That one was just so dramatic and it was just juicy. When we got in to record it, it was just amazing to watch it all come together."

Every time she enters the studio, Carrie is mindful of giving her fans the very best she can. "In today's market, you can't just have an album with three singles and filler," she says. "You have to make sure every single song is amazing and could potentially be a single, which makes all of us work harder."