The box was on its last legs. Crumbling at the corners, wilted at the top, sagging at the sides.

But you kept on playing.

It had been a fort, a rocket ship, a puppet theater; and, most recently, an ice cream truck. And I realized, as I watched my 3-year-old serve pretend ice cream scoops to her siblings through a makeshift window, that the droopy cardboard structure I had almost thrown away had done that elusive thing that all parents want all toys to do: it had occupied my children long enough that I could have a moment.

“The type of toy matters when it comes to independent play,” says Bryana Kappadakunnel,  a Los Angeles-based LMFT and creator of RaisingChildrenYouLike.com, an online class for parents of young children. "There’s a saying: 'The more a toy does, the less your child does; the less a toy does, the more your child does.'”

What that means is that parents should steer away from toys designed to do or teach something and look for toys that let the child lead the way.

“What is so powerful about independent play at any age is that the child’s imagination is being enhanced,” Kappadakunnel said. “If we can take the pressure off of play to be academic and instead see play as how a child learns to regulate their body, how a child learns to interact with others, how a child learns to occupy themself . . . play then becomes this rich, wonderful work that is fascinating.”

Want to set your child up for play—and get a few minutes to yourself? Here are our picks for the best toys for independent play:

Best for Sensory (and Imaginative) Play: Play-Doh Kitchen Creations Magical Oven

Play-Doh is great for solo sensory play (you can't beat that squishiness!); it's also great for building creativity, as kids can make and mold whatever they imagine. This simple set gives kids a great prompt: food! Littles will love making little cakes and pies, and putting them in the tiny oven.

Cost: $29.99 on Amazon

Best for Budding Artists: NextX Kids Easel for Two

Your little artist will be inspired if you leave this easel out for them with paint-filled cups, ready to go. If you're not brave enough to let your child loose with paint (we've had our share of painted footprints on the floor), the easel has a chalkboard and dry erase board that is a little less risky. Another bonus: The legs are adjustable, so it will grow with your child.

Cost: $58.64 on Amazon.com

Best for Future Engineers: Mega Bloks First Builders Big Building Blocks

These big blocks are perfect for tiny fingers and will teach little builders how to connect block pegs so that they can create towers, houses, creatures—or whatever they imagine.

Cost: $14.90 on Amazon

Best for Kids Who Like Trains: On Track USA Wooden Train Set

Playing with train sets not only builds your child's imaginative skills, it also hones fine motor skills and dexterity as they learn to move the tracks around to create all sorts of configurations. This set—which comes with its own storage box—has an assortment of tracks and bridges as well as various houses, buildings, people, trees, bushes and signs.

Cost: $52.99 on Amazon.

Best for Warm, Summer Days: Step2 Cascading Cove Sand and Water Table

Water play is always a winner—especially when it's warm outside—and sandboxes are an instant imagination-igniter (just think of all those castles to build! Treasures to bury! Mountains for little figurines to climb!). This sand and water table combo is a perfect pairing; it even has an umbrella to keep kids' skin safe from the sun, and a lid to keep the sand clean and dry when not in use.

Cost: $111.79 from Walmart.com

Best For Active Kids: Eezy Peezy Monkey Bars Climbing Tower

Not all solo play has to busy the mind; little bodies need to move, too! Active kids will love climbing on, swinging off, and dangling from this geometric climbing dome. Or, throw a blanket over the top and you've got an insta-fort. Win-win. It's not super high off the ground so it's perfect for little climbers.

Cost: $155.58 on Amazon

Best for Little Chefs: Step2 Best Chefs Kitchen Playset

There's something about pretend kitchens that capture every kids' imagination, and this set comes with enough accessories (bowls, pots, pans, silverware) to keep your little chefs busy for hours. There's even a recycling bin to get those eco-conscious habits started.

Cost: $69.99 on Amazon

Best for Portable Pretend Play: Melissa and Doug Scoop and Serve Ice Cream Counter

Who doesn't love ice cream? Your little scooper will have a blast assembling, topping and pretending with this ice cream shop play set. Even sweeter, the "shop" is small enough to tote around the house, which makes it easy for playdates and travel.

Cost: $33.49 from Amazon

Best for Music-Makers: Smart Wallaby Toddler Musical Instruments Set

Your home will be alive with the sounds of music if you let your little Mozart have a go with this 25-piece musical instrument set, which includes a tiny trumpet, triangle, castanets, a tambourine and a xylophone (plus a backpack for taking it to go). Experts say playing with musical instruments can build hand-eye coordination, motor skills and creativity—but your kids won't care about any of that; they'll just be making music.

Cost: $31.99 from Amazon

Best for Role Playing: 11-inch Newborn Baby Doll

At 11-inches, this New York Doll Company doll is sized for toddlers and life-like with different skin tones to choose from. You'll love that there are no noises or battery-operated features. Pair it with a baby doll crib or stroller and your child can practice taking care of baby all day.

Cost: $24.54 from Amazon

And Then, Of Course, The Best Toy Ever: The Cardboard Box

Every kid everywhere agrees: Cardboard boxes—the bigger, the better—are the coolest toys out there. The only problem? The best ones only come with refrigerators. That said, if you want a great "toy" without the new appliance, just go to your local Best Buy and ask if there are any discarded boxes you could haul away (there might even be some out back in the parking lot).

Or, if there's someone moving into your neighborhood (or a new home being built), ask the property owners to put aside any furniture or appliance boxes for the sake of your kids. Most people are happy to oblige, and your child will be rocketing to the moon in no time.

—Melissa Heckscher

Melissa Heckscher is a writer and mother of three who loves painting, writing silly stories, and sleeping in (the last of which never, ever happens). Visit her online at melissahecksher.com.