Under the stairs, through the playroom, is my "Toy Of The Day" storage closet. The door knob on this door is a locking knob and toddlers are not allowed in there. I doubt they even know the door opens because I only open it before or after hours.
In the photos below, you can see the list I taped to the inside of the door. I've listed all the toys I keep in the closet and divided them into different categories for each day. You can view the list at Google Docs.
The photo below is looking into the closet. You can see mostly all the types of blocks I have.
You will also notice the picture of Whoopie Goldberg that is visible even when the door is closed. That is the "Tattle Whoopie"--I tell the toddlers to go cry and complain to her. They do!
The next photo is of the closet going under the stairs: tunnels, balls, blocks, cars, etc. It's very hard to get good photos in such a small space. It's also hard to keep this closet in order. One thing falls in the aisle and it gets too hard to move around in there.
Each morning I choose a "toy of the day" off the list of whatever day it is. These toys are all toys that the children can freely play with, without help or close supervision. They usually have a lot of pieces (like Legos, blocks, cars, etc.) so having only one set out is enough. They also have a "wow factor" because they are not out everyday.
We do have everyday toys out all the time (in the photo below). They are general toys: dolls, stuffed toys, trucks, teethers, stacking & nesting toys, housekeeping toys, etc.
After the day is over and the toddlers have gone home, I put away the "toy of the day". I start the next day with another "toy of the day".
The toddlers love to see what's new each morning! It keeps things new and fresh.