A bathroom needs less light than people expect and needs it in different places. One centre fitting lights the floor and puts every face at the mirror in shadow. A well-placed pair either side of the vanity, or a single fitting set forward of the mirror rather than directly above it, lights the face evenly. That is the fitting you use every day, so it goes in first.
Shower and bath. One moisture-rated downlight over each is usually enough. It is a sealed fitting with a diffused face, so steam and splashes stay outside the housing, and it is switched with the room.
The open floor. A small bathroom is often one or two fittings in the open area; a larger ensuite with a separate toilet is a handful, spaced so the light overlaps at head height and does not stripe the tiles. Fewer fittings, placed properly, beat a grid.
Colour. A neutral white makes a bathroom look clean and shows skin tones honestly at the mirror; a warm white suits a bath you soak in at night. Tri-colour fittings let us set one at install and change it later without touching the ceiling.
Dimming. A bathroom is one of the few rooms where a dimmer earns its keep: full brightness for shaving, a low glow for a 3 am visit. We fit a trailing-edge dimmer matched to the fittings so the low end does not flicker.