Free Soccer Play is one of the most powerful and effective ways to develop the skills of your players. Traditional soccer programs typically focus too much on structure and drills, which is detrimental to player development.
The concept of Free Play has been pioneered by JoyOfThePeople, which are the current U19 futsal national champions. Listen to this short clip by John O'Sullivan (ChangingTheGameProject) for some background on why Free Play is more effective that traditional practice structures.