You might not have all the answers when you're just starting out, but listening to feedback can certainly help. That was the key theme Sarah Kauss, CEO and founder of S'well and Ben Chestnut, CEO of Mailchimp echoed at the iConic conference on Wednesday, an event co-sponsored by CNBC.

Kauss's New York-based water bottle company expanded from a $10 million brand to one generating $100 million in annual revenue in just a couple of years. She noted an inflection point for her company came from an inquiry of a magazine that wanted to feature S'well. It asked if S'well could supply bottles with additional colors for a photograph. At the time, the company had just one. She knew then that the company needed to expand.

For Chestnut, co-founder of the Atlanta-based email marketing firm, meeting with customers and hearing what they need has been key, and it'd be a mistake to ignore them.

The entrepreneurs went on to share more of their top advice for starting up at the Inc. event. Here are just three of their top tips:

1. Remember your early vision.

Most entrepreneurs know what makes their products special when they start their companies, Chestnut said. However, it is during the growing stage that many of them forget their vision. He also emphasized the importance of keeping the independence of the culture of the company, citing it as one of the reasons he did not take money from investors. He says they often wanted to shape Mailchimp according to their own vision, and that just wasn't going to work for him.

2. Don't over spend on plush office space.

Both Kauss and Chestnut started their companies in their apartments before they started hiring more employees. "There are plenty of beautiful places to have a meeting," Kauss said. In other words, don't spend money on office space, if you don't need it, she said. Chestnut agreed, noting that his company made similar calls. "We were always scared to death someone would show up," he said.

3. Lean on your spouse for support.

Work-life balance may work better when you bring work issues home, as ironic as it sounds. In fact, Kauss hired her husband, Jeff Peck, in 2016. His strong points are her weaknesses. Her husband, who is S'well's COO, is better at managing operations and supply chain, while Kauss sticks to creative. Of course, working with your spouse has its challenges, and is definitely not for everyone, she said. For Chestnut, he says simply talking to his wife about issues at work improved his life as an entrepreneur.

Correction: An earlier version of this post misstated Sarah Kauss's husband's name and title. His name is Jeff Peck, and he is S'well's COO.