tile:

I would use darker tile on the floor and carry that into the shower. Then use the lighter tile on all the shower walls. You could put an accent tile in the darker shade somewhere on the shower wall, but I think if you are going for a modern look you don't need to do that.

That tile is really beautiful, esp. in the first photo you posted at 2:14. I like bright bathrooms. Of the 5 color variations you've posted, I think top-right and bottom-right are the most appealing. The darker floor will help ground the room.

For contemporary - I like top left and top right options. Top left is going to add an impression of depth to that part of the room like an accent wall.

Does anyone know what tile is shown in the first photo at 2:14?

I like the bottom left, just visually the pattern pleases me the most. But without giving any thought as to which one brightens the room more. However, that can also be addressed with lighting.You didn't say how big the shower is, we are building a 60 X 36, and in hindsight, I now wish I had put 2 LED shower lights in there instead of just one.

As to how to lay the tiles, with 12 X 24's you have to figure out how much variance there is from tile to tile. It has been recommended that you NOT lay them in a normal running bond, but have them offset by 1/3, rather than by 1/2. The problem is lippage, which I think I can see in the third pic down, which I gather is exaggerated when you do a running bond.

Regardless of which way you lay the tiles, you MUST have your walls perfectly flat. We are in the process of DIYing our shower, and now DH is realizing that flat means flat and sees where he made some mistakes by not shimming on the 2X4's before screwing on the cement board.

Am also assuming you are not planning on using the 12 X 24 for the shower floor?

You could straight-lay the floor tile using the darker tile and continue it into the shower floor, Then do the vertical offset pattern in the shower using the lighter tile. We just did that in our master bath reno and it turned out gorgeous, and with a less-busy look than having everything with a vertical offset lay. The only difference is we used a glass tile border as an accent around the top of the shower and around the separate tub. It turned out great. I don't think you'd need any embellishment to keep the clean modern line you're after.

For a totally different idea. We also used two different colors of a 12x24 tile. Three walls are beige tile with a navy stripe and one wall is navy with a beige stripe. This picture gives shows the general idea.

This post was edited by dekeoboe on Mon, Jan 13, 14 at 21:39

I used darker tile on the floor, into the curbless shower, then lighter tile on the walls of the shower. As I lay them out, that seemed to push the floor out the furthest, making the room look more spacious.

linelle, that picture is from houzz
https://www.houzz.com/photos/pacific-heights-mediterranean-contemporary-bathroom-san-francisco-phvw-vp~1047676-Heights-Mediterranean-contemporary-bathroom-san-francisco

dekeoboe and Katy60, thanks for sharing your photos. they are looking great

I like the dark floor and the lighter walls. I like top left and top right. I would be inclined to use simple layout of color, instead of putting in accent colors on the wall. Though the one with the back window wall is might work for me. Dark recedes. Depending on how big the shower is, would dictate how much action (color changes) I put into there.

Saw this pic on Houzz. Though for a tub, gives you an idea of the 2 tone tiling.

[Modern Bathroom[(https://www.houzz.com/photos/modern-bathroom-ideas-phbr1-bp~t_712~s_2105) by Boston Interior Designers & Decorators Melissa Miranda Interior Design

To use the linearity of the tile to make the room seem bigger, it should use the lines and colors like this:

@hollysprings thanks for the mock up!