I put them in a banker's box with rubber bands and those big black clips, along with the notebooks I carried around while I was working on them, and I stuck them on a shelf, out of the way. (The banker's box is not an accurate representation of how many drafts there were of each, or of how hard I worked on them. Each had somewhere between 4 and 9 drafts--printed out, that would be a LOT of paper. I only printed what amounted to about two drafts per manuscript.)
I love them. I loved working on them. I learned a lot from them. But they're done. I don't think I'll ever return to them. I don't need them taking up space on my shelf, or getting in my way when I'm looking for notes that have to do with my current manuscript. Or taking up valuable space in my binders, for that matter.
And I don't really want to think about them anymore. I feel like they represent a less confident me. The me who got upset and shaky whenever a critique partner made a comment I wasn't sure I agreed with. The me who cried over form rejections (okay that still might be me, but I'll never tell). The me who didn't yet believe "someday, real, actual people--READERS--will read this."
This is the part of murdering your darlings they don't tell you about. The time when the entire project needs to be put away--gently--into a box, because maybe it's not who you are anymore, or because it'll never amount to what you wanted, or because you got better and it's not going to grow as fast as you will.
Don't be afraid to say goodbye and move on.