My daughter's room is just about finished. I think everything has been moved in that will be moved in. All that's left is a trip to the donation station and we will get our garage back (an living room, and hallway).
We didn't make a clean break with everything. She has one box of toys that she admitted she hasn't missed, but she knows she'll recognize them if she opens the box and she would feel too sentimental to donate them right now. We left them in the (shoe) box, in her closet, and in six months or so we will revisit the box. Anything that is too special to discard will be kept, but in the meantime her room is that much tidier. She also dedicated a shelf to display items, but she chose a small shelf, and some of the display items will be stored and display will be rotated, like at a museum. That way she can keep a tidy room and also keep the things she most values.
I am happy to report that my daughter did thin the collections she kept. Only her favorite doll clothes will be kept, and only her favorite display items. About half the items in each collection were purged, and I am confident the remaining items will be of greater value to my daughter in the future. I did not push her to get rid of any item, even if I did not see the value of the things she decided to keep. I would rather she have a second purge later on than resent the decluttering process, and me, because I pushed her to get rid of something she valued.
On another front, my husband also felt the decluttering bug today. He cleared up the desk area, and moved a lot of sentimental items out of our living space. When our dog died several years ago the vet gave us the ashes, a paw print in clay, a personalized wooden box (for the ashes) and a velvet bag (to protect the box), We have scattered the ashes, but we still had the box with the dog's name, sitting empty on a shelf. This is not the best way to remember our dog -- we're actually more likely to remember him at the beach, or when we see a dog the same breed -- and we will not feel a loss for disposing of the box. My husband also got rid of a couple crafts the kids made when they were very young, and instead uncovered a photo of him and the kids together. I prefer the photo to the crafts made in preschool, and if that's the way we both feel we should not hang on to the crafts just to prove we were present during our children's childhoods.
I'm really excited about all the sentimental items we're decluttering. I don't feel I can declutter these things alone, but I am happy to remove the items that "should" hold sentiment in favor of activities that are important and items that actually do hold memories.