I love the Cubeicals. I got them at Target, but you can find them other places too, I think. They're fabulous! My kids would get frustrated because they'd try to put their books on a regular-sized bookshelf, and they'd fall down. Each space in the Cubeicals is only about 12" wide, so it's a lot easier for toddlers to put books on them. For the toys, I can put things with multiple parts, like train pieces or balls, in the fabric bins and just slide them into the slots. Then I can have a toy in each open slot, and it's nice and tidy. With just one toy in each slot, it's easy for kids to see where to put something. I have a wooden dresser that holds dress-up and doll clothes, and kitchen set accessories live in small plastic drawers next to the kitchen set. Larger items (of which we only keep a few out at a time), like wagons or bigger trucks or dollhouse, sit on the floor in a corner. I personally really hate toyboxes, where toys of all sorts just get tossed together, so we don't have any of those here. (I don't, however, sort and fold dress-up clothes or kitchen set stuff; those things get tossed into their respective drawers, but at least if the kids want a particular item, they're only searching through similar items to find it.) The Cubeicals are really flexible and can grow with your family as your needs change, which is great.
Number one key to keeping toy clutter under control, though -- it isn't the organizational system (though that does help a lot). It's the number of things available at any one time. We, like probably most people, have too many toys, even "good" ones, so only a limited number of toys are out at any one time, especially ones with lots of pieces. Less to clean up, and when something comes out that hasn't been out for a while, it's quite a hit. Kids stop seeing things after a while, I think.
Number two key: do a little clean-up every day. If the kids dump out the train set, for instance, with its many pieces, the first day, it's played with a lot. The second day, maybe some. If we clean it up after a day or two, all the pieces are still pretty much in the same place, so it takes two seconds to put away. If we leave it for a week, though, somehow, that same number of pieces gets tracked around the house and mixed in with other toys, and then it takes much longer to put it all away (and it's more overwhelming for the kids to do themselves, whereas if it's only a small mess, I can say, "okay, put all the train pieces away," and they can do it).
Mama to four: 10, 7, 3, and 1