Watch the The Art of Listening online guitar lesson by Jennifer Batten from Rock Sauce For Lead Guitar
There are a ton of different ways to listen to music and at different times you'll focus on different elements. Sometimes you'll really hear the lyrics more than anything if it's vocal music, and the rest will fade into the background. Other times it's the groove that hits you most. Try to listen consciously to different levels. Perhaps one time through, you can focus on someone's vibrato only. How fast is it? Is it consistent? How wide is it? Where is it placed in the phrase? Another time focus only on the bass and drums and be aware of which rhythmic hits they play together. This will expand your overall awareness of what others do, and can give you ideas for your own music.