I always time my ruins whenever I spot one before either my scout or villie gets it. Many people think it's lack of macro, but it's not. I'm waiting. Waiting for a certain resource to become the lowest... either by manipulating the city by queuing up villies, or by building a farm or researching something that takes up timber, etc. Everything is planned for how I want to start my game.

Fast Classical raid or rush... I need at least 2 or 3 Ruins, and always food.
Ancient Age Heavy Infantry rush... I need usually 4 or 5 Ruins, and either food or timber, but most of the time, food.
Booming start 1/2/2/2 before Classical, I need around 6 or 7 Ruins in order to get to Classical around 5 minutes. I need Food or Timber, and never Wealth.

The only time I need Wealth from Ruins is when I'm doing my Greek fast 2/1/2/2 Medieval... which I can usually get in around 5 minutes, and with a few heavy cavalry ready for raiding.