The sound of your classical guitar can be improved in several ways. First, regular maintenance of your instrument is crucial, this includes cleaning and changing strings as needed. High-quality strings tend to produce a richer sound. Secondly, ensure that you’re utilizing proper guitar technique, such as good finger positioning and pick usage. Also, remember that the guitar's sound can be affected by the room's acoustics, so consider where you're playing. Finally, professional setup and adjustment of the guitar by a luthier can significantly improve the sound quality.