Personal preference. Mine is that all the same way looks worse than having it mixed. When you have pattern repeats, uniform direction emphasizes that. It looks more realistic when you turn them randomly.

Sophie, by looking at my picture you would advise to turn some and have them go all different ways?

Some people make great effort to make it look like one giant sheet of marble. Its a personal call.

One giant sheet of marble as a look is only possible with natural stone that is sequentially cut. Porcelain, even good faux marble, will always have pattern repeats. Therefore it's best to try to not pick patterns that will accent that fact. Turning them all randomly, and checking to be sure that you don't have repeats too close will give you a look that isn't so obviously faux.

I agree with Cabot & Rowe. "Sometimes you feel like a nut....sometimes you don't."

In some instances, following the vein is good. Oftentimes, you need to mix them to break up the room. Try "Dry Laying" them to see what you prefer.

Poorly worded question - it's not a 'personal choice'. Veined tiles have an edge matching system so the pattern continues to the adjacent tiles. I have checked all mine and that is how they were done. Non-matching looks dreadful.

^^^some of the tiles have it but not all of them

thanks. That must be a new thing; why would anyone want a hotchpotch of random lines and blotches.

I'm laying luxury vinyl 12x2 and straigh rows to where veining connects Looks much better.