Mud was one of the toys I played with my friends, preferrably red mud. We would use the mud to make icicles with chopsticks. It was a great game of pretending.
Another popular toy was the slingshot. We made it out of tree braches shaped in a "Y" or used thick wire. I still know how to make ammunition out of paper. TIt wasn't a safe toy since we'd often shoot at each other.
An active toy that most teenagers had was a metal circle with a metal stick as a guide. We used a thick metal wire and bent it into a circle. Then we make a metal stick with a hook at the end to push the circle. We would push the circle to race against each other or crash into each other to see whose circle was still rolling.
Those are some economical homemade toys I played with was a kid in Guangzhou, China. I wonder if kids are still playing with them.