It is a common misconception that more input (practice) creates more output (improvement). 

This is rarely the case. 

Instead of putting in more time I would encourage you to consider what type of work will yield the most improvement. It most likely will not be playing a piece beginning to end, or repeating the same warm up you have used for years. Rather, it will be an area of focus that you have decided upon because you analyzed your skills objectively.

Playing through pieces the same way you have been will improve your playing, but it will be slow. 

Take a step back from your normal routine and answer this question: 

What area of my musicianship can I work on that will yield the biggest improvement the fastest? 

Analysis? Sight reading? Re-fingering? Finger independence training? 

Only you can decide, and when you do you will improve.

Let us know what you decide in the comments below…