My sister and I only ever had good-quality toys and books, which we were taught to keep in good shape. They survived years of playing with them and, lucky for us, have been in storage since then. Once my husband and I move to a bigger place from our current flat, I plan on having a shared office and kids' room from the beginning, where the few pieces of clothing that actually survived will be stored alongside with afore-mentioned books and toys. Trinkets etc. have been very selectively saved, but most of them were given or thrown away.
We won't need any more toys from anyone, so if people want to give gifts, they will be encouraged to invest in bonds or such instead, or maybe give an event of some kind. I've always known that I want kids one day, so if physiology says no, then we will consider adoption. Once the kids grow old enough to have a room of their own, the office would move out, I imagine.
These toys and books will be used as long as you can still use them and financially it's been a lifesaver, so once they aren't needed anymore, what can still be used will go to basement storage or similar. Not all new toys are "bigger and better", so I assume a grandchild would be able to play with them too. Again, trinkets etc. are a completely different chapter, and that's where you can teach the kids the value of having no clutter around. I view for instance a lego toy as a childrens' computer or baking pan of a sort, something truly useful, whereas the "toys" that come out of Easter eggs are completely useless in my opinion, junk really.
One thing which was completely clear to everyone while growing up was the concept of a play room. We didn't even call our room "kids' room" but it was denoted "play room". It was our domain and the home of our things, so to leave our stuff all around the rest of the home was a complete no go. Of course we were allowed to play elsewhere too, but once we were done, all the toys were carried back to the play room. I intend to live by this one day too, even though I know many parents welcome toys just about anywhere in their homes. In my opinion, it's a good way of teaching kids to be responsible of their things and to take good care of them as well. As a bonus it helps the cleaning process and mom is a happier person for it (dad doesn't care as much as mom :) ).
I know this replies to only parts of the OP but it's a complex topic. I can't wait to become a mom though :D
