From an article by Mike Woitalla

5. Greet each player when they arrive in a way that lets them know you’re happy to see them. 

6. Always end practice on an upbeat, happy note. (Even if they drove you absolutely crazy). 

7. See the game through the children's eyes. This will remind you that your main objective is helping them discover the joys of soccer. And not to expect a 6-year-old to play like a 16-year-old! 

8. Do not yell instructions at them! Do not coach from the sidelines during games! This interferes severely in their learning process. It also makes you look rather silly -- an adult screaming at 6-year-olds while they’re playing.