Screen time and don't (let them) create accounts on services with age limits. You need to get them used to the concept of screen time and the rules by which yo

Screen time and don't (let them) create accounts on services with age limits. You need to get them used to the concept of screen time and the rules by which you get more of it as early as possible in life so it becomes ingrained. When they're old enough to buy their own phone and pay for their own phone bill, they can have free use of their device.