Deliberate practice is characterized by several elements, each worth examining. It is activity designed specifically to improve performance, often with a teacher’s help; it can be repeated a lot; feedback on results is continuously available; it’s highly demanding mentally, whether the activity is purely intellectual, such as chess or business-related activities, or heavily physical, such as sports; and it isn’t much fun.
With or without a teacher, great performers deconstruct elements of what they do into chunks they can practice. They get better at that aspect and move on to the next.
Practicing something without knowing whether you are getting better is pointless. Yet that is what most of us do everyday without thinking.