This, believe it or not, is actually some of the best advice I’ve ever received, and I’m afraid to say that I received it so long ago that I have no idea who initially suggested it to me. It’s exactly as it sounds, though – you don’t actually delete anything you’ve written.
By this, I don’t mean that every word must be kept, and certainly not in the initial manuscript it was written for. What I do mean, though, is that when you are editing your work, it’s a good idea to have a separate document open as a personal slush file. Whenever you cut a significant bit of writing from your story – say, more than a couple of sentences – try cutting and pasting it into that slush file instead of getting rid of it altogether. That way, when the time and inspiration is right, you can use it for another story, or as inspiration for another scene or character.
I guess this is a long-winded way of trying to stress that our creative juices should be valued. Just because a particular scene or piece of dialogue doesn’t fit one story or a particular place in that story doesn’t mean it’s not going to be good – albeit slightly edited – somewhere else. And, speaking from experience, it’s well worth it. I’ve adapted countless thoughts, conversation snippets and whole scenes from old stories to fit new ones, and usually they’re a much better fit the second or third time around, possibly because I’ve had that extra time to get them right.
Well, that’s it from me. What’s the best bit of advice you’ve ever received about your writing? I’d love to hear it. 
I’m not going to answer your question but will agree with your advice! I maintain a file called ‘murdered darlings.doc’ in parallel with every manuscript I draft, for the reasons you explained. This also makes it psychologically easier to excise sections you love but which just don’t fit, because you know they’re not lost forever.
In addition, as a part of the editing process, I scan the ‘murdered darlings’ to see if any should actually be rescucitated and reinstated. Many times I’ve done this. Because of this, I now find it easier to deal with sections I’m not sure about because I know they can be recovered: the initial decision to delete is no longer final.
Precisely. It’s much easier to be ruthless while editing when you know that anything you delete can be re-inserted later, if need be. I must say though that I love your name! Murdered darlings. So evocative, yet so accurate. I wish I’d thought of that one.
I must confess that ‘murdered darlngs’ isn’t all my own work. The advice to ‘murder your darlings’ was originally made by Sir Arthur Quiller-Couch about 100 years ago. I remember it well.
Ah, fair enough! Though at least you were familiar with the quote and thought to apply it to this particular practice, so you can get credit for something. Me, I just call those files “deleted scenes”. As you can see I am sometimes lacking in imagination.