The short answer
Culture is built in small, daily decisions — not in one big plan. Name your values out loud right now, even if the team is small. Decide what you will and won't accept. Repeat it. Those early choices set the mold. Waiting for the team to 'settle' before shaping culture means the culture shapes itself.
You're building the plane while flying it. That's real. Research on team culture shows that the early stage of a team — when roles are still fluid — is actually the most powerful window for shaping how people work together. Knowledge sharing, trust, and emotional tone between teammates all tend to lock in early. Once patterns form, they're hard to undo. Acting now, even imperfectly, beats waiting until you feel ready.
Marcus Aurelius put it plainly: don't undervalue yourself so much that you hold back from doing what is right. You already know what kind of team you want. You don't need a perfect org chart or a full headcount to start living those standards out loud. Every time you let a bad norm slide — or call out a good one — you are setting culture. The question isn't whether you're shaping it. You are, right now, either on purpose or by accident.
This week, pick one value you want the team to live by — just one. Say it in your next team meeting. Then show it, not just say it. If you want people to be direct, be direct first. If you want people to ask for help, ask for help first. Small, visible acts from you set the tone faster than any policy will.