It's a busy time for Yahoo CEO Marissa Mayer--but you wouldn't know it to hear her talk.

Perhaps to the disappointment of some, Mayer didn't weigh in on her company’s potential merger with AOL or the activist shareholder urging that move during her Advertising Week conversation with Robert Safian, managing director of Inc.'s sister publication Fast Company. But the long-time executive offered plenty of tips on advertising strategy, and more importantly, management roles.

Here are her top four pieces of leadership advice:

1. Be passionate and focused.

If a leader isn’t passionate, employees won’t be either. "Our mission is making the world’s daily habits inspiring and entertaining," Mayer says. "Which people come to work at Yahoo to build on that mission? Those who are inspired by that, and you can feel that passion in the products."

2. Figure out your company's DNA.

Like many top executives, Mayer isn’t her company’s founder. She uses a genetics metaphor to explain how to maintain a company’s legacy while simultaneously making it your own: "When you're coming into a company, and you know have to do a transformation, what you really want to do is look at the company and say, 'Okay, here are the parts that the company does well. How do we get those genes to hyper-express? The genes that are getting in the way, how do you turn those off?'"

3. Maintain your startup mindset.

Yahoo is one of the biggest corporations in the world, so remaining dynamic is a bit of a challenge. "It will sound strange, but we think of ourselves as the world’s largest startup," Mayer says. "Startups have to move fast. Startups organize into small teams that are really dedicated to particular products or investments, and that gives people a large sense of ownership, responsibility, autonomy."

4. Let your employees do their jobs.

Mayer, who has an M.S. in computer science, misses writing mobile apps and code--but recognizes that it’s not her responsibility anymore. "Management is defense," she says. "You basically say, 'This is the direction, this is where we’re heading,' and then it’s my job to get everything else out of the way. All the other things that can become a distraction keep us from executing well. Get those out of the way, because the team ultimately needs to run in that direction and execute well."