There are a number of times when you are super busy, and arrive at the field without having setup a Practice Plan for that practice.
In these situations Quick Practice comes to the rescue. You'll be able to select from a list of practices you've marked as a favorite and boom.. you have a practice ready to go. Just start the timer, and conduct the practice. After its over, you'll be able to assign players and make any edits you need to make.
So - how do you mark a practice as a favorite? In the detail/recap view you simply turn on the Favorite switch, and the practice is marked so it will show up as a Quick Practice when you need it.
All of us here at BTC have practices marked as favorites for just this reason, and we use them often.