Don't read (too much)! I know this goes against that which many have said above, but is sifting endlessly through the symbolic representations of other's thoughts really going to assist immeasurably in the articulation of your own? Have you stopped reading this?
Reading others and writing oneself should be kept conceptually and practically separate.

My thoughts are exactly these when it comes to composing music. I must keep my head clear of other 'notes' and melodic phrases or they will (and have) creep into current works. This doesn't mean I won't actively seek inspiration from other methods of "approaching" representing the idea... but, often I'm my own inspiration.

If I wanted something that sounded like Copland I'd dig him up, prop 'em up on a chair and ask him to write it for me!