Stop automatic downloads from App Store for my multiple devices

I have a few different iPhones, iPads, and iWatch synced to my Apple ID and every app I download on one device is automatically downloaded on all the others. How may I stop the automatic downloads from the App Store for each device? I have an iphone 6; iPhone 7; ipad air 2; iWatch 6; iphon3 12 pro max under my single apple ID. I just want to be able to turn this off completely or individually for each device. Help!