How to get your Toddler and Preschooler to Pick up the Toys

I often find myself harried to get things all done at once after supper is done: cleaning up the kitchen, cleaning up the toys, giving the kids a bath, reading the kids a bedtime story, getting the younger one to sleep, then relaxing. It doesn't help when I have a little tyke underfoot, wanting to be held. Or my 3 year-old bringing in her Pooh Mobile for the 5 time - - and me almost backing into her for the 5th time. It also doesn't help when one or both of them is asking for milk or juice. Or the younger one wants to get all of the pots and pans out of the cabinet, or undo my well-organized storage containers.
One word helped me out more than I could ever imagine: delegate. When I'm cooking, not only do I get the kids to start cleaning up their toys at this time, but I might also get their help setting the table or emptying the dishwasher (though sometimes I don't want help with these things if there are breakables).
So how do you get a preschooler, or even a toddler, to start cleaning up their toys before supper - - so that it's not an issue when you should already be putting them in the bath shortly after supper? Sometimes it takes a bribe (namely stickers or pennies in their piggy banks), but more often than not it just takes getting down on their level. You can't just tell a preschooler, or better yet a toddler, to clean up her toys. To say this is to ask them to do some monumental, overwhelming task. It's like asking you to file next year's tax return this year.
You have to break it down. For my older child, I might say to get all of one type of toy picked up. She knows where the puzzles go, where the dress-up clothes go, where the leggos are supposed to go... I'll say, "Avalyn, can you please go pick up all of the leggos?," and "When you get done, come back and I'll tell you what to pick up next." Sure enough, she'll go pick up all of the leggos, and come back. Then I'll tell her to put up the puzzles. The first time I asked her to pick up the puzzles, she put the pieces where they belonged, but didn't put the puzzles away. It only took once to show her how to stack them on top of each other and place them in the cabinet.
With my toddler, I tell her to do more simple things. I walk her to the front room, where the odds and ends toys go. They usually end up right in front of where they go anyway. I simply tell her to put everything from off of the floor into the drawers. She does it, and even seems proud of herself when she's done. The leggo tub, or any other container where she can just throw things is a game in and of itself. I don't think she even realizes she's performing a chore!
If your child(ren) don't know where things are supposed to go, or you don't really have a clear system, get some containers and label them. If your children, like mine, aren't old enough to read, print up pictures to label the containers. It isn't too hard for a child to see a picture of dress up clothes and know that's where they go. They can see a picture of a crayon and know that crayons go in a certain box. A picture of a doll can indicate where the dolls should go.
It's not that they don't want to clean up or help around the house. In fact, it's a built-in instinct for children to want to please and help out (sometimes when you DON'T want their help). They simply need someone to communicate to them in a way that they understand. You can't make it complicated. When they're under 4, I would forget having everything color coded or in some other sophisticated sorting protocol. Just be happy that they're willing to help out, and devise a system that they can understand. Happy cleaning!