Starting a business is a daunting prospect. It can be expensive, frustrating — and lonely. To counter that last part, at least, Adelaide Lancaster and Amy Abrams foundedIn Good Company, a community workspace for women business owners in New York City. Over the years, they’ve learned a lot about what makes entrepreneurs flounder, and what makes them soar serenely over the rough patches. In their new book, The Big Enough Company, they outline four secrets that happy entrepreneurs know:

1. Stamina matters. “Running a business is a marathon, not a sprint, and it can take a while before you see the financial fruits of your labor,” says Lancaster. “Sure, you can work around the clock and sacrifice everything else in your life for the sake of your business, but is that sustainable? Bolstering your endurance requires you to adopt a ‘work smart’ mentality and commit to valuing yourself as much as the business.” A few best practices: learning to set boundaries, delegating work, keeping a clear focus on goals, and employing small steps towards progress.

2. Success isn’t about size. “Our culture tends to glorify size and fixate on numbers. This is even true in the small business world where entrepreneurs often tout and compare things such as top-line revenue, the number of employees and locations, and market share. Entrepreneurs often pursue these metrics at the expense of their own satisfaction.” Lancaster and Abrams encourage entrepreneurs to generate their own definitions of success, which may include numbers and metrics but acknowledge that “bigger isn’t always better.” What do you want out of your business?

3. You must learn to say no. “Savvy entrepreneurs recognize that that not all opportunities are created equal,” Lancaster says. “Many are merely distractions that drain the company of important resources, such as focus, energy and time. Others may even imperil the whole venture. Successful entrepreneurs cultivate their own restraint, saying no quickly and frequently in order to stay on track.”

4.  Admit what you don’t know (comfortably and openly). “Most successful entrepreneurs spend a lot of time identifying what they don’t know and, more importantly, how they can find out,” Lancaster says. “Openly admitting knowledge gaps is as important as comfortably asking for help. Most people are hesitant about displaying this much vulnerability, but entrepreneurs know that their survival depends on it.”