I've chosen stone look floor tiles (soft grey) which have "veins"/ slightly darker lines running through - about 4 variations. Is there a right or wrong way to lay the pattern? I like thelook of the pattern heading in one general direction, even if they don't match/meet exactly. Or is random placing the norm? I know it's not natural stone, but I'd like it to look as natural as possible. They will be on bathroom floor and one shower wall, as well as the entry to the house. Any ideas or comments, greatly appreciated. Is it ok to ask the tiler to follow a "pattern"?