If it is clear that changes should be made, for example in personnel, ask several people in the organization for their advice before doing anything. Even after building confidence and experience, asking others for advice is rarely harmful and always helpful, if it is considered seriously. The most enduring working relationships are those built on honesty and consistency. It is tempting to give into insecurities by pandering to employees, but the loyalty it may engender is fickle. Be quick to note when others have done good work, but don't feel that each day must be started by making the rounds telling people how nice they look or inquiring about their children or pets.
People can smell insincerity quickly.
They respect those who respect their own time. Praise publicly, but criticize privately. Criticism should be clear and helpful, not punitive. If someone makes a mistake or produces poor work, it is the manager's responsibility to let him know it and why. First, look for aspects of the work that can be praised.