We are tiling our sauna and there is a slopped floor drain. We are using 13" x 13" tiles.
How do we go about tiling around the drain?

When you get near the drain you will need to cut a few tiles into pie shaped pieces that will fit on the compound slope.

Remember here to allow for the thickness of your tile at the drain. In other words, float your mortarbed approximately 1/4" to 3/8" below the lip of the drain so that the tile will install flush to the drain. Continue this process around the entire shower pan. It will take some time and patience the first time you do it, but the reward is that you'll have a beautifully sloped shower pan. You can find lot's of information here Cicliot