Musicians have admitted it for hundreds of years that stringed instruments improve in tone and responsiveness from age and playing. In 1821, Jacob Otto in Germany published a small book describing his experiment with a mediocre violin, wherein he tied pieces of gut string around the neck to act as frets and make the sound brighter. He then played every note possible fortissimo repeatedly, for hours, singly, as octaves, double stops, 2nds, 3rds, 4ths, 5ths, 6ths, broken chords, etc. After a few days of this, the violin was so greatly improved that the concertmaster of the orchestra at Gotha, Germany offered him a large sum of money for it.
You can improve your instrument the same way by vigorous playing. The vibration forces all the parts to vibrate at greater amplitude, relieving some of the tension caused by gluing everything together along with strains generated by spruce drying faster and shrinking more than maple. Never leave an instrument in the sun or in a hot car trunk. The heat and shrinkage may split the top. This ‘playing in' of a new instrument is something that may be apparent immediately, but it is generally conceded that the improvement continues for ten to fifty years, depending on how much you play it. A weak or thin note gets better, and it takes less bow pressure to produce the same sound level. The sound comes quicker with the touch of the bow, and the quality of the tone improves. If you are lucky, the development of that sublime clarity may occur, that lets the sound stand out against an orchestra, and ring from the ceiling to the audience. Vigorous playing breaks down the tightness and stiffness, and eventually it plays more easily. (Don't bother with the frets).
This treatment will not cure the defects of poor wood, bad varnish, poor workmanship, or bad fitting and adjustment.