The way I tackled the tiling was that I left a space large enough for 2 rows of tile along the bottom of the shower wall. You don't want to start right at the floor since the floor isn't level. Instead I will cut the angle of the floor into the bottom row of tiles where it will be less noticeable. By starting 2 rows up, I was able to make sure the rows were level (I used a few boxes of tile and a board to set my first row of tile, making sure it was level.) DON'T ATTACH THE BOARD DIRECTLY TO THE WALL OR YOU WILL PUT HOLES IN YOUR WATERPROOFING!!
Days 2 and 3 was more of the same and I finished with this much complete (at least it looks better as the red is covered up):
And by the end of week 1 this is as far as I had gotten.
Some specifics about this tile. It is chiaro tumbled Turkish Travertine marble. I ended up getting it at Lowe's because even though it was about 60 cents per square foot more than the tile shop (I paid $4.26/sqft), but I will be able to return any that is unused. I also didn't have to pay any shipping or handling and could buy it by the individual square foot. I knew that would be important because the individual tiles are very VERY different. I wanted to make sure I could pick out the best tiles without huge imperfections, holes and cracks. I originally purchased almost 33% more tile then I needed, knowing I would return a lot of it.
I used 1/8th inch spacers since the variation in tile size was quite large. I originally wanted to use 1/16 spacers (the smallest you can reasonably use) but I knew with the rough edges of the tile it wouldn't work out.
To set the tile I used the same mortar I used to patch the walls, which is specifically designed for travertine.
Budget for this part of the remodel:
Travertine 3x6 tiles (102 sq.ft. at $4.26): $434.52**
Renovation total to date: $736.50
**I will probably only need approximately 70 sq.ft. so this is an overestimate of costs
UPDATED 12/16: I was able to return $119.56 worth of tile after completing the shower and tub. This credit is reflected in the budget in this post.