After graduating from Princeton in 2002, Ellie Kemper moved to New York to try to make it as an actor. While she auditioned and performed improv comedy, she worked at the now-closed Crumbs Bake Shop on the Upper East Side, and learned a few things about lattes.

"I don't think it's around anymore? I know it's not around anymore, but it was a great cupcake shop while it lasted! I don't take credit for that, but I had something to do with it. I was serving the cupcakes," Kemper tells CNBC Make It. "I had the early shift, 6 a.m. to I guess 2 p.m., and I got kind of good at making lattes. I wouldn't say, I mean, I wasn't hired for my ability to make lattes, but I learned how to do it, and you'd be surprised how many people are angry when they're going in to get cupcakes. You'd think, 'Oh they'd be happy,' but no."

That description of her time behind the cupcake counter is a sharp representation of Kemper — fast paced, self-deprecating, humble, hilarious — as well as many of the characters she's played. Kemper got her big break when she landed a role on "The Office," playing the peppy Erin Hannon. She says she spent her first big paycheck from the show on two pizzas from Pizzeria Mozza.

Since then, Kemper has reached a level of success most actors only dream of, including her recent turn as the innocent but unstoppable title character in the "Unbreakable Kimmy Schmidt." This October, she's releasing a collection of essays, "My Squirrel Days," that looks back on growing up in St. Louis, quitting field hockey and her breaking into comedy.

Here, Kemper shares three things she says she's learned from working with comedy legends like Steve Carell and Tina Fey: