If you would consider buying "The Dangerous Book for Boys" then you will want to learn how to make a good slingshot. I learned how to make slingshots when I was a girl, though they weren't as accurate as this one. I loved learning survival skills. You never know when your ship might be wrecked and you might end up stranded on a desert island, hopefully with a pocket full of rubber bands.
I recommend this craft for upper elementary children at the youngest. They need to be responsible. They also need to be strong, to hold the slingshot steady. If they can hold it steady, they can shoot it where they want, following the important rule, "Never shoot in the direction of any person or animal."
Find a stout forked stick, about six rubber bands, and a strip of leather, canvas, or felt for the sling. I used a piece of felted sweater scrap I had in my studio, as you can see below.
Join three rubber bands for each side of the sling. Make another loop on each end to attach the rubber bands to the stick.
Now, give the child your safety rules and collect some projectiles. I favor acorns. They make a resounding smack when they hit a tree trunk in the woods, my favorite target. But you can make this a safer toy by using balled-up paper for shooting, or small nerf balls.
Stand a good distance from your target. You don't want your projectile to ricochet back towards you. Hold the slingshot straight in front of you, with the fork square to your body, and try to keep it still. Put your projectile into the sling, and pinch it from the outside of the sling with your fingers to hold it in place. Look through the fork at your target, pull the sling way back, holding your stick steady, and let it go. I find this slingshot amazingly accurate and just as much fun as it was when I was a girl.