I've been mostly in kitchens and bathrooms on this forum since joining recently but I have a flooring question: I've coughed up for pebble tile flooring for my whole bathroom floor. I have a creamy white that we can call the 'field tile' and then running through it I want the glazed blue/green pebbles in a 'meandering river' type of deal. I may have asked this somewhere on here before, but does anyone have any idea how I could make a template for plotting this out or do I just sit down and start moving the tiles around til I like it? And if so, how does one 'mark' the tiles so that everything ends up where it's supposed to when it's crunch time? I really hate to screw this up... I've never spent so much on tile in my life (it really tested my theory that if you have a small house you can buy a little higher end since you don't need so much of it).

Also, does anyone have any advice on choosing grout? I want the blue/green to really stand out and the white to be more as a 'supporting member' to the blue/green. I'm think tan for the white stones and... what... for the blue/green?
thanks in advance!