A quote from Reinventing Organizations, about a few unwritten principles for coaching, in Chapter 2.2: Self-management (structures), page 70:

• It’s okay for teams to struggle. From struggle comes learning. And teams that have gone through difficult moments build resilience and a deep sense of community. The coach’s role therefore is not to prevent foreseeable problems, but to support teams in solving them (and later help them reflect on how they’ve grown in the process).
• The coach’s role is to let teams make their own choices, even if she believes she knows a better solution.
• The coach supports the team mostly by asking insightful questions and mirroring what she sees. She helps teams frame issues and solutions in light of [the company’s] purpose and its holistic approach to care.
• The starting point is always to look for enthusiasm, strengths, and existing capabilities within the team. The coach projects trust that the team has all it takes to solve the problems it faces.

• Frederic Laloux, Reinventing Organizations