When leading a team through a project, how do you foster a growth mindset?

Encourage failure and sharing failed experiments.
Improve psychological safety.
Factor in life delays and slow down deliverables if possible (budget 5 hours instead of 6 per day).
Demonstrate how you have a growth mindset as well

Consistent Communication!

entrepreneurship

Minimize processes for the people that you've got around you. Avoid putting up all these barriers and forcing them to do process after process. You can't take all the process away. You've still got to have structure in there, but minimize it as much as possible so that they're not bogged down in bureaucracy and being mentally fatigued before they've even started.

Think incrementally about forecasting. You often hear it's impossible to forecast a project, so we're going to do a minimum viable product or we're going to do a sprint. Keep thinking like that, but also you've got to have an idea of the bigger picture at the end of the day. Make sure the team understands the vision and they're aligned to it.

Don't be dogmatic. Don't get stuck on, we must be agile, or we must be waterfall to deliver this. Just accept that circumstances at certain times are going to demand a different way of doing things and a different approach to doing things. Don't be dogmatic about the milestone or goal you set, be prepared to adjust it and adapt it.

If you can't coach the mindset or the team, poach it. If you haven't got the people around you that you need, if you've identified skills gaps, if you've identified people who are missing and you haven't got the opportunity to coach them, just go out and poach it.