Before you begin to play check your how body weight is centred. Mindfulness of posture and relaxed hands and fingers. The Alexander Technique is a method of being aware of how much tension is present in your body and being able to use techniques to optimise your playing without injury.
Analyse your piece of music for tempo changes, key changes, accidentals, dynamics and pattern with either hand. What is the composers' intent with the music.
Begin slowly. Play the piece beginning hands separately usually right hand first. Prepare more difficult bars of music by isolating and repetatively playing until it is right. Then lead into by playing a bar earlier.
Dont practice for too long. To get the maximum value out of your practice keep it to the length of time you can stay focussed and keep concentration levels going.