Ken Bingham, the Drexel University creative-writing professor who also taught me to edit, teaches that writers must be willing to "kill your little darlings." I need to commit mass murder and I know it.
In this video, Ira Glass of NPR's "This American Life" discusses the importance of editing -- not just words and phrases you love, but also throwing out story ideas and even dumping stories in progress in order to free yourself to create pieces that achieve the level of quality you want.