How much time should you practice your instrument?

It's more than you think.

After each lesson that I do with my guitar students, I remind them to practice. Usually, they will say, "Okay." Well, to me, that immediate reply is not a convincing response to my request. I will then ask them how much time do they plan to practice their guitar and work on the lessons I just gave to them. A glazed look will fall over their eyes, and th…