Though most people’ ideal ensuite is spacious and bright, many urban apartments present a different reality. Narrow bathroom ideas might be hard to come by—but rest assured, there are tons of ways to transform even the smallest space into a luxurious–feeling lavatory. All it takes is a little extra ingenuity and creativity, like the smart strategies below.

1. Use pastel palettes

To make the most of the wall space, Thomas Christiaen designed a custom vanity unit paired with shelves, and used paler shades of blue and beige.

Photo: Juan Jerez

Bright colors can work wonders by reflecting light and creating a greater sense of space, especially in narrow rooms that get little daylight from small windows (or no windows at all).…