ᐅ Tiling an Exterior Staircase Leading to the Front Door: Patterns and Tile Sizes

Hello everyone, I want to tile my staircase and I am wondering about the best tile layout and especially the tile size. Currently, 30x30 cm (12x12 inches) tiles are installed, but there are only a few options available in that size. 60x30 cm (24x12 inches) is a common standard and has the largest selection, but I’m not sure how well that would work. The problem is that the tread depth is 42 cm (16.5 inches). So I would need a bit more than one tile if I lay them across the width. 60x60 cm (24x24 inches) tiles would be better for that, but then at the top landing by the door it wouldn’t fit quite as well. The staircase is 1.515 m (4 feet 11.8 inches) wide and 0.73 m (29 inches) deep, or 0.92 m (36 inches) at the recess. Does anyone have suggestions for the best tile size and layout pattern here? I’m attaching a picture of the staircase.

This setup is ideal for a single-piece granite slab. Above all, it provides excellent support.