Tile direction

We're building a house, and plan to install 18' porcelian tile on a diagonal in the kitchen and keeping room.

The tile resembles a natural stone, and has some veining similar to marble.

Any suggestions on how to attempt to orient the grains?

While looking at some tile sites, it appears (and I may be wrong) that on 4 tiles they try to point the grain toward the center. Perhaps this keeps some running together with an overall effect of randomness?

Thanks in advance...

Steve in Louisana

You will achieve the best results by placing them in a random fashion. The eye is quick to pick up a pattern, which is unwanted if you are hoping to achieve the look of real stone..