Effective Over Quantity
We have to be talking, again, about practice.
In fact I have been talking a lot about effective practice with my students today. It does not matter which instrument you play, when you get to a good standard you can spend hours and hours "practising".
Often when I go through scales and arpeggios, or even pieces we have played a while, with a student I hear
"I ALWAYS make that mistake."
and once again I find myself repeating the words I have said for 28 years now (wow time has flown)
If you always make that mistake you are practising getting better at that mistake. In the end the more you do anything, the better you get at it. Slow effective practice will always produce a better, faster and more accurate result.
Instead stop, correct and repeat the correction until it is automatically correct.
Then don't let a mistake creep in, more than three times in a row it is starting to become a known error. In time it will be so natural it sounds wrong, when its right and right when its wrong.
Stop, correct and repeat the correction until it is automatically correct. It may seem to take longer, but it will pay off in the end, your weakest sections will become your strongest parts of the piece.
Effective practice is better than hours practised.