Surround yourself with people who are good in addition to being good at what they do. You can’t always predict who will have ethical lapses or reveal a side of themselves you never suspected was there. In the worst cases, you will have to deal with acts that reflect badly on the company and demand censure. That’s an unavoidable part of the job, but you have to demand honesty and integrity from everyone, and when there’s a lapse you have to deal with it immediately.