I have four kids aged 1-8. It feels as though our place is overflowing with toys and clothes. I think that the children don't play with their lego/playmobil etc as the amount is overwhelming, and that they would be better off with half of the amount that they have.
We live in a 3 bedroomed apartment, so space is an issue.
Any decluttering also has to be done in secret as DH, and all four grandparents (who buy most of the kids things) all get quite upset when they see me carting stuff off to charity shops. My inlaws, for example, still have DH's childhood toys in their attic, and trying to give them to us!
(I do also hide/phase out lots of things and use them in the shoebox appeal at Christmas time, for example, but again, that is a secret).
Please tell me how you all do it!