Practice routine

When I first decide to play a piece on the piano, I work on it for 1 hour on one day.  Then I work on it for half an hour for one day, then 15 minutes for several consecutive days. It takes concentration and discipline to work on something for an hour, but then if you know its notes fairly well you can spend less time. After a while, I can sit down and play the piece by memory a few times over in much less than 15 minutes. I like working on very easy pieces that I can learn this way. If I spend the first hour and don't make headway, then I need to choose something easier.