This is a simple idea, but it really really works.
If you're practising a piece of music but you're not sure how to make it better, then just ask yourself these questions:
The reason this works so well is that the absolute most crucial elements of the music - timing, frequency and sound, are prioritised.
And when working on these elements, there's usually more you can do to refine your interpretation.
Most techical 'improvements' that you make whe playing the violin can more often than not be traced back to the precision and fine calibration of these elements.
So take the time to listen - really listen! - to what you are hearing when you play through (or video record) yourself, and adjust what you are doing accordingly.