1. Set a high bar for quality. Before you start recruiting, decide what attributes you want and define as a group what great looks like. A good rule of thumb is to hire only people who are better than you. Do not compromise. Ever.
2. Find your own candidates. LinkedIn, Google+, alumni databases, and professional associations make it easy.
3. Assess candidates objectively. Include subordinates and peers in the interviews, make sure interviewers write good notes, and have an unbiased group of people make the actual hiring decision. Periodically return to those notes and compare them to how the new employee is doing, to refine your assessment capability.
4. Give candidates a reason to join. Make clear why the work you are doing matters, and let the candidate experience the astounding people they will get to work with.