Edit: Some people suggested I compile my comment into an article... so I published it here: https://news.layervault.com/stories/30825

I helped build the design team at Disqus and now I'm helping build the design team at Teespring.

Always make sure you're hiring exceptional people (that applies to all departments, not just design). People who have a passion to create and build will be your smartest employees. It's better to hire someone who has a problem solver's mindset but lacks a specific skill than to hire someone who has that skill but lacks a problem solver's mindset.

Ask yourself, "what does this person do better than I can?" Make sure each designer brings a unique skill to the team. When everyone is good at something different, everyone settles into projects that fit their strengths and they won't run into ego battles.

"Unicorns" can be great, especially when the company is small. Unicorns can code and design, but don't forget the more designers are coding the less they're designing.

As a company grows, you want hire more specialists. Unicorns who are "T" shaped (i.e. they have a broad skill set but are still very good at one thing) will experience fewer growing pains.

With a few exceptions, I have often found Unicorns to be slightly less skilled in the artistic and visual department (myself included). Sometimes it's useful to have one person who is just really good at branding, visuals and interaction design without knowing how to code.

Don't make exceptions. Even if you're extremely desperate for help, a bad employee will cost you more time and money than what they temporarily saved you.

“Steve Jobs has a saying that A players hire A players; B players hire C players; and C players hire D players. It doesn't take long to get to Z players. This trickle-down effect causes bozo explosions in companies.”

This leads me to my conclusion for how to structure your team. You've hired the best possible employees you could find. Everyone brings unique skills to the table. Do you really need to structure the company like a traditional agency? A flat organization structure keeps egos in check and shows your employees you value them equally. If you really did hire the best, let them know they can use whatever external title they want (Senior, Lead, etc...) after they move on from the company.

Last, don't be intimidated. Building a strong team is time-consuming, tedious work. But let me tell you, it's some of the most satisfying work you'll ever have.