I just finished the marble Floor for the Entrance Hall.
The next day was cutting day. I cut the black marble into 1 " by 1/4" tiles, and the White marble into 1" x 1" and 1/4" x 1/4" tiles using a metal ruler and a sharp utility knife.
The next step was to cut a subfloor in illustration board to the dimensions of the room. because the tiles are not perfectly square, it was important to have guide lines on the subfloor to make sure the pattern was as exact as possible. I took out some graph paper with 1/4" x 1/4" squares and glued it onto the subfloor. Next, starting with the very center of the room, I glued the tiles in place with a regular glue stick.