The hardest thing to do in a startup = stop doing everything.

The hardest thing to do in a startup = stop doing everything.

When Sara Blakely was 29, she quit her door-to-door fax salesperson job and invested her $5,000 life savings in her new company, Spanx.

Her first decision was to focus on what she was best at: Promoting her product. She says “The best thing I ever did was to hire my weakness” so she could focus all her time on her strength.

While other startup founders might have been busy trying to run their company or fix their systems, Sara was...