Don't do it at all, if I could change one thing and my kids still turn out as great as they are it would be to never give them video games, now that there older 18, 20 I hate them and hated them as teenagers. They get so into them and then that's all they want to do. I asked them all through high school have you seen the light of day yet and do you remember what fresh air smells like? Ya mom we had to go to school today remember I saw it on my way. Ugg I have wonderful kids but they still play way to much and don't try and tell me you can liner it. Because when they get a certain age you can't. They turned out amazing but I still hate them.
We set limits on video game playing for our kids, and they work very well. As long as they live in my house, they have to abide by the limits we set.