Be more than a designer. Be realistic. It may be with the best intentions, but aiming for perfection can cost more than it gives you.
Things take time, embrace it. Slow is pro. Use what you’ve done to inform the next thing and if the data is unanimous don't be afraid to change what you’ve become attached to.
Process is everything. But not just any old process. It’s important to find a way of working that’s right for you and your team. No one wants to get stuck in meetings that could have been an email or drown in post-it-notes. Play to your team’s strengths and if it doesn't get actionable results it might not be worth doing.