Suppose when one of your underlings employee makes a mistake, don't lord it over them, assume the mistake as your own, even if it isn't technically yours. What you're doing is creating a culture where your employees feel comfortable making mistakes. This is a very important concept:

Doing this allows your employees to innovate and, ultimately, to learn or grow. Workers who learn from their mistakes will grow to become better workers; those who fail to make mistakes in the first place usually play it too safe, never venturing out into deep water.