Perhaps you’ve been brought in to clean up the mess of the last executive director. Maybe you were hired following the retirement of a beloved leader and feel a bit overwhelmed by the big shoes you have to fill. Whatever circumstances led to your taking on the leadership post at a nonprofit, your success will depend on building strong relationships and developing a firm understanding of the organization — its past, its present, and the future you will shape.

Here, six nonprofit and foundation heads share examples and advice from their own experiences as new leaders.

Christine Márquez-Hudson took over as president and chief executive of the Denver Foundation in January 2016. Ms. Marquez previously served as chief executive officer of Mi Casa Resource Center, which offers job training and business development to the Latino community in Denver.

  • Get to know your board — well. Ms. Márquez-Hudson made this a priority in her first few weeks on the job. “I want to get to know them and allow them to get to know me on a personal level,” she says. “I want to know what talents, skills, and gifts they bring to this work, so that I know when to call them.” She believes establishing those close ties early on will allow her to work with each board member in a way that capitalizes on their individual strengths.
  • It’s the little things that count. “Sometimes low-hanging fruit can make a big difference,” she says. Right off the bat, she changed the frequency of staff meetings. It was a small change, but it quickly showed people she was listening and being responsive. And during her first week, she ate lunch in the staff lunch room — another small gesture that meant a lot to staff members. “It shows that you’re interested and care and that helps build trust,” she says. She hopes that trust, built on such gestures, will come in handy when it’s time to make difficult decisions.

Suzanne Nossel, chief executive of the PEN American Center, took the helm of the literary writers and editors group in 2013 after leading Amnesty International.

  • Embrace your outsider status. The situations that strike you oddly as a newcomer will soon seem normal, so in the first two weeks, make note of anything that seems surprising, strange, or nonsensical. “Take a step back in the early days. The first few weeks are your chance to observe as an outsider,” she says.
  • Start by creating a strategic plan. “It’s a good way to help you flip the organization inside out,” she says. The strategic planning process offers opportunities to collect data, to interview a wide range of stakeholders, and to gather input. “The vision that emerges is more of a shared vision, as opposed to the vision of an individual,” she says. “It allows you to move forward from a well-rounded position of knowledge.”
  • Get to know your donors and peer leaders. Identify the really important players and your counterparts outside your organization, and get to know them in the first six months on the job. “You never know when you might need to call them,” she says. And likewise with your donors or major prospects — prioritize that list, and get to know them in one-on-one situations: “A phone call or a meeting can be a low-stakes way to engage someone and open the doors.”

Reynold Levy, president of New York anti-poverty group the Robin Hood Foundation since October 2015, previously led such organizations as Lincoln Center, the International Rescue Committee, the AT&T Foundation, and the 92nd Street Y.

  • Treat everyone like a top donor. “Treat your trustees and your employees as if they were clients and users of your services, as if they were your most precious donors,” he says. Some of them are, but many are not. Regardless, you have to be available when they are. “If they want to have breakfast across town, if they want to see you on a weekend or on your vacation day, then that’s a small sacrifice to make.”
  • Study up for stakeholder meetings. Thoughtfully preparing for one-on-one meetings with staff or donors requires a significant amount of time and energy. It also pays enormous dividends — in terms of both what you learn and the way in which you bond with new people. Learning about the organization and its history enriches and informs your conversations, he says. “Demonstrate to whomever you’re talking to that you took the time and made the effort to really prepare to see them,” he says. “You’ll find cues and clues to connect, rather than that conversation being superficial.”

Gina Ross Murdoch became president and chief executive of the Multiple Sclerosis Association of America in early January 2016 after serving as deputy executive director of the New Jersey chapter of the Leukemia and Lymphoma Society.

  • Learn from your predecessor. The board arranged a transition so that there was some overlap between Ms. Murdoch and the previous leader, who had been with the organization for 16 years. Use such opportunities to ask questions about the institution’s background, she says. Her predecessor provided analysis of the board and its structure and introduced her to the organization’s main vendors and partners. “Gather the prior leader’s thoughts on areas of opportunity and potential areas of growth,” she suggests.
  • Establish communication channels as soon as possible. Ms. Murdoch requested weekly meetings with the organization’s executive committee and senior management team as a way for her to benchmark activities, set goals, and give those leaders a safe space to voice concerns. She also started monthly all-staff meetings, which end with question-and-answer sessions. Each of these meetings provides an opportunity to build trust. “Set up a communication schedule as quickly as possible,” she says. “That proactive outreach to set up a feedback mechanism shows that you’re open to it, that you welcome it. That will set a really good tone going forward.”

Anthony Smith is chief executive of Cities United, which aims to eliminate violence-related deaths of African-American men and boys. Mr. Smith started in November 2015 as the organization’s first executive director after leading the safe and healthy neighborhoods department in the Louisville, Ky., mayor’s office.

  • Ignore imposter syndrome; have confidence. Being a new leader, sometimes you question whether you should be there, he says. Remember that people hired you for a reason. It’s OK that you don’t know everything — you have a team around you that can provide information and support. “It’s your organization,” he says. “Lead it, but do it in partnership with your team and your board.”
  • Don’t act prematurely. Give yourself time to get acclimated to what’s going on. That doesn’t mean being overly cautious, but rather proceeding with respect and humility. At the same time, a new leader should not be afraid to take action quickly if it needs to happen. “It’s OK to make decisions in the first 90 days,” he says, “but make sure you’re doing it in a way where you know you’ve had time to assess what’s going on.”
  • Bullet 3

Karen Marben is executive director at Genesys Works Twin Cities, which provides job training and work opportunities for economically disadvantaged high school students. Ms. Marben, who started in June 2015, came there with a background in sales and marketing at for-profit companies.

  • Evaluate staff roles. Though she says she didn’t make many staff changes in the first few months, she made a point of meeting with each of her 27 staff members to get an assessment of the organization from their perspective, see where they fit in, and learn their career aspirations. Her goal, she says, was to answer the question “Are the right people in the right seats on the bus?”
  • Make every decision with constituents in mind. The organization’s founding director encouraged her to first get to know the students the program serves. She started the job just as an eight-week summer training program was beginning, so she sat in, allowing her to get to know the organization from the students’ point of view. “That really helped steer some conversations early on,” she says. “It helped ensure that the students were the top priority and at the center of every decision.”