My top five
While I don't disagree with the three in the article, I put them further down on my list.
#1. Know your people. Loyalty is hard to come by, and circumstances aren't always as they seem. Get to know your people: what drives them, what interests them, what their specialties are and what they'd like to do. This will help you put the best people in the right places. Know where to find the round peg for the round hole.
#2. Allow others to contribute. You don't have to control every detail about the project. By backing off a little, you encourage others to step forward with ideas and become valuable contributors.
#3. Recognize achievement. From an office Nerf war to white water rafting to some PvP in your video game of choice, make sure there is a light at the end of the tunnel. This applies to individual projects as well as group ones.
#4 Set clear goals. There is no excuse for managers who do not set clear and realistic expectations with their subordinates. You can't manage someone without knowing 1)what it is they are supposed to do 2)by what day 3)using what tools.
#5. Give honest, timely feedback. If someone in your group is underperforming, find out what is keeping that person from achieving. Work with them where possible to help make up the difference. This is an opportunity to reinforce #1 and also helps them know you want them to succeed. It also leaves failure squarely upon their shoulders.