A CORNERSTONE activity is one that can serve as the foundation for your entire practice and with a few modifications you can build an entire practice session around this activity. Here are activities you can use with children 7 and older at any level to teach dribbling, dribbling to set up a pass, short inside/outside push passes, receiving-ball control, cooperating with a teammate, etc.
Activities: Multi-Gate Game - 4v4 Plus Goalkeeper - Coach Pac Man