1. Do not give computer to kids till they are 12.
2. Time box their usage.
3. No internet.
Don't!!! If you restrict like this, kids will go to their friends place with the pretext of having fun and have screen time there. You give something to kids and time box it every time and it becomes a habit. This is exactly how kids get addicted to computers and games. Come the time or day, they expect you to give them computer or phone and they hate to do anything else during that time.
I have two boys, 7yo and 9yo. I used to set a time for computer usage and games and time box it to exactly an hour. You know what happened? Every day kids wake up and ask 'will we get to play today' and if the answer is yes, they would wait for that time specific time to play games. For last 2 years, we changed the way they get screen time.
1. It is entirely random. There is no specific day of week and there is no specific time. On weekends, sometimes we play right after breakfast, sometimes it is afternoon and sometimes it is extended session late evening. Many weekends, we won't play at all.
2. No time boxing. Some day we ask them to stop after 40 minutes, some day, they go on for more than an hour, extending to 2 hours on some days.
3. Roblox, iPad and phones games are strictly off limits. They can play on iPad or iPhone under special circumstances. One such was last weekend. Controller was not working and kids did not play pc games for many days. We got new board games (Rummy sub, ticket to ride) and kids played that a lot with us. They wanted to play video games and we allowed iPad and phone for two days. Each day they played for an hour and a half I think.
4. Couch co-op games like 'It takes two', 'hotwheels', 'overcooked 2', 'f1', 'fc 24' etc are allowed, no dumb games.
5. Youtube is banned on TV, they can watch Netflix hotstar etc. This is to keep them away from watching really really dumb videos.
6. No one in home is allowed to play reels or shorts. This includes us, our parents. I would keep my kids away from this addiction as long as I can.
7. When there are revisions in school, screens are off limits. When there is lot of home work, screens are off limits.
Result of this is that they mix up by their own. One day, they play on computer, other day they watch TV and if they get too much of screen time, they get bored and then for few days they play board games with us (have a big collection of board games) or we go into nerf gun fight. All this is after they do physical activity (playing with neighbor kid) and finish their homework. Last weekend, they used scratch 3 to recreate a story of a cartoon in iPad. They treat these devices just like toys. If they don't use them, they don't get into state of hopelessness. If they get them, they do not get excited and hug and kiss us.
Give the kids freedom to explore good stuff on computer but always watch over their back nudging them in right direction. Keep it random and tune their minds to the fact that playing for little more time and not playing at all are absolutely normal.
Restricting technology and screens for kids till they are 12 is old method. In our office, there was this session given by a lady who specialized in child psychology. When we asked her about how to raise kids like how we grew up, she told us not to do that. Her logic is simple. Our world and our childhood was entirely different to what it is now. We cannot apply that logic to our kids, it just won't work. Guess what, she is absolutely spot on. Just because we grew up with desktop does not mean kids must also start with desktop. We using phones and laptops while making kids sit on desktop is not fair tbh. Teach them to use ergonomic setup (I make my kids to maintain distance from screen and use controller to keep their eyes safe), not restrict them to desktop.