In order to express a song, classical piece, solo, etc. with good tone and phrasing a guitarist must find the most effective, efficient, and functional fingering as possible. This does not mean the “easiest” way – like only using the first 2 fingers or going out of your way to avoid the pinkie. Try to find the best map and path for you fingering and picking. Many times, your choice of fingerings and picking WILL DETERMINE THE QUALITY OF SOUND you get during a song. Sometimes, a bad choice can build a barrier between your technique and a quality sound. Also, inefficient fingerings will put more strain on your hands and cause fatigue, as well as make the song seem way for difficult than it has to be.
I recommend you practice finger exercises, picking/rhythm exercises, and finger independence exercises (hugely important!) to prepare your hands for making the best fingering choices, as well as performing music with an effortless sound and smooth technique.