Use ceramic tiles with less gloosy finish for more grip.

Tiles are naturally slick because they have an almost perfect finish. Stone is naturally more pitted and uneven. It is this "rough" surface that allows for better grip. A low-slip finish on a tile is worth the same as a "polished" finish on stone. Both stone and tile can be made slick...or low-slip. It all comes down to the finish.

Stone will require a bit more maintenance as it will require resealing from time time. The choice is yours. Stone can be magnificent. Tile can be as well...if you pay enough money for it.

Go with a low slip porcelain as it is more durable than a standard ceramic tile and does not require the maintenance of stone.

I've had smooth and textured ceramic, and both can be very slippery when wet. Get sample tiles to take home and try out. Wide grout lines can help, but you may not care for the look. I have saltillo tiles in the kitchen, but the grout lines are about an inch wide.

Thank you