Start from the beginning with a solid foundation, in my opinion. Your initial team sets the tone for how you mean to go on from there. The personalities of your first ten people will set the personality of your company, whether you realize it or not, whether you mean it to or not. I think this is just how groups of people work, kind of a rule of thumb for how organizations grow.
npm hired me early, and I have been in the Valley for a long time and seen both successes and failures. I've been lucky to be at the sidelines of some fantastic engineering teams. I was nobody and I did nothing much at General Magic, but the people I watched at work there went on to do gigantic things. But I've also seen stupid teams do stupid things, and I managed to learn from them too. So my contribution to npm has been to help steer the engineering side of the company in the direction I think is best-- which has upsides and downsides. I think there are perfectly wonderful people who would have a bad time at npm, and whom I would not judge for having a bad time. (For instance, if you don't thrive on the written word as a way to communicate with your colleagues, you're not going to be happy with the writing-mad culture at npm.)
First and foremost, I hold that the humans who work on the software are more important than the software! We work to live; we do not live to work. The best work is done by well-rounded people who have interesting lives, who come to the office refreshed, who treat the humans around the well, who are in relaxed and happy places.
I try to tell my colleagues how much I enjoy working with them every so often. (Dear colleagues, if I haven't said it to you recently, please hear it now. I enjoy working with you yes YOU.) Give this a shot with a colleague you enjoy working with! Tell them! Tell them why!
I love writing software. I remain amazed and delighted that I can earn a living doing this thing that is so much fun. I want it to stay fun for me and for everybody around me. This simple desire drives a lot of what I do. I hope it rubs off.