I would say take it out of the bedroom. Don't let them go to bed with their devices. If you start that at a young enough age, it becomes something that they just get used to.
A lot of parents are just leaving their devices in the room. Not only is that sleep deprivation for the kid because they're addicted to these devices but it just sets up really negative patterns.
I have a 12-year old daughter. She just started junior high school, and she doesn't have a cellphone. She's the only one of her friend group that doesn't have a cellphone. She begs me every day and I'm terrified.
I know I'll eventually have to get her that cellphone, but in the meantime, I'm just not finished talking about it yet.