I stopped trying to mimic other artists songs because whilst I could certainly get good renditions of the likes of James Taylor and Paul Simon I got bored of doing it. Now I play other people’s songs my own way, although I don’t stray from the essence of the song.
For me, a very good example of an artist taking a song and making it his own is Ryan Adams’ cover of Iron Maiden’s ‘Wasted Years. In fact Ryan Adams plays loads of covers and gives them his treatment.
https://www.youtube.com/watch?v=1iBe53ruE1g