For example in my BooBoo Pets game I ask users to rate my app every 20 minutes. And since the game is about taking care of a pet, it doesn’t interupt a high scoor or something like that. I didn’t have a single bad review because of this reason.
On the other hand on Square Skills I ask users to rate may app after they die 4 time. The dialog prompts while they are on the high score screen, so it doesn’t interupt the gameplay experience.
I can only think about a game with levels where you could ask them to rate your game after they die a few times or pass a few levels. I think that covers it all.