One very helpful thing I’ve done is create a Toy Library. Very similar to a toy rotation, but a lot easier to manage. My kids have a basket of toys in the living room (things like Buzz, Woody, Potato Head and other dolls and dinosaurs), they have a drawer each in their bedrooms for their special toys that they are not required to share with each other.
And to keep my sanity, all the multipiece toys are stored out of reach, in a cabinet, in a locked room they don’t go in unsupervised (the business office). The Toy Library is filled with puzzles, letter games, blocks, cars and tracks, trains and tracks, LEGOs and the like.
By keeping the toys that suck to sort and put away out of reach, our kids only play with one type of toy at a time and clean up isn’t too overwhelming for them. When the kids are too overwhelmed for their own mess, who ends up on clean up duty?