After our tile buying expedition in town yesterday, we came home and DH began doing the tile layout in preparation for the actual tiling. You always "dry fit" or layout your tile before you begin installing it to make sure everything goes together and that there are no surprises.
He started with the bare Hardi-backer covered tub surround.
Then he screwed a "first row" board onto the Hardi-backer that was exactly one tile tall and level. Then he dry fit the horizontal rows on all three sides of the tub surround, then continued up the back wall in horizontal rows to make sure the tiles would meet the ceiling properly. (That's our accent row with small glass tiles in shades of blue at the top.) He'll start laying tile on top of the first row board. After all the tiles are laid on that wall up to the ceiling, he'll remove the board and lay that row last.