How often do you hear a word of praise? Not as often as you'd like I'd bet. The problem is that we tend to emphasize the negative and only punish bad work. Sure we should expect people to do good work. Still no one likes to be taken for granted. If you praise good work, it only takes a minute and the payoff is that you've expressed what you really think and made someone's day. Not a bad payoff for 30 seconds of effort.
It will also develop a spirit of generosity in you. Remember the overworked word virtue simply means a good habit. MrAristotle pointed out that of all the things that we seek as goals, only happiness is sought for itself alone. You can be a vehicle of happiness, which is a wonderful thing to be.
Here's an oft-overlooked way to praise good work. If you accomplish some task jointly with someone, especially if that someone is a junior, give him the credit. (PraiseBasedLeadership) Everyone will know you were responsible for the success as much as he. And if you're the senior, probably more. In popular stories, managers often do the opposite. (ManagersAreMonsters?) Yet a good manager gives credit where credit is due, takes pride in his team, rather than trying to take credit himself for their accomplishments. -- TimKing