Oh, toys. Many toys. Many big toys. The most effective toy storage solutions include dividing and labeling everything.
Since most preschoolers can't read, these won't be your file-folder labels. Instead, use picture labels of socks, shorts, shirts, and dinosaurs help your preschooler know where things go.
For example, I went online and found the Thomas the Tank Engine home page, printed it out, and taped it to my son's bin of Thomas toys. Now, he knows exactly in which plastic tub to find and return his Thomas trains.
Here are some of my favorite ways to stash and display his bulky and hard-to-stash playtime favorites:
Toy Storage Solutions for Big and Bulky Playtime Favorites