Of all the rooms in the house, the bathroom needs the most flexible lighting scheme. It should be bright enough to enable you to put on make-up or shave, but you don't want to take a relaxing bath under a 100 watt bulb. It must also be safe.

European safety regulations are rightly rigorous, stating that bathroom fittings must be completely encased to avoid shorting and electric shocks, and double insulated with the bulb and all metal parts covered. Don't ever be tempted to use a conventional light fitting that's not intended for bathroom use. Light switches must be either outside the bathroom or fitted with a pull cord.

When the lighting in a bathroom is done well, it can look stunning; just think of all the materials that were made to be bathed in light - porcelain, glass, stainless steel and marble. Be careful, though - with all those reflective surfaces, it's easy to create a glare nightmare.

If you've inherited a dingy, depressing bathroom or want to update your old one, there are lots of things you can do with the wiring that's already there. Plan the lighting carefully if you're fitting a brand-new bathroom. If the new tiles have been laid over the cabling, for example, it will be very hard to change.

To maximise natural daylight, take down blinds, fussy curtains and unnecessary window dressing . If you're worried about being overlooked, a cheap solution is to frost your window - either pay a glazier or use a frosting-effect spray from DIY stores.

If you have only a harsh central light operated by a pull cord, one of the easiest ways to create instant ambience is to ask an electrician to fit a dimmer switch just outside the bathroom door instead.

Replace existing fittings with frosted ones - you'll immediately get a lovely diffused light.

Stud the ceiling with several low-voltage spotlights or downlighters, which wash the walls with light. Downlighters cast pools of light onto the surface below and are great for water and glass. Get your builder to put in a false ceiling to hide the wiring.

Fit downlighers with a dimmer. You don't want to be blinded by the light when you go to the loo in the night.

To light your mirror, install a row of lightbulbs, dressing-room style, around it. They give a good, even light from all sides. If that look's not your style, fit diffused wall lights on each side. Either way, avoid a single strip above the mirror or you'll end up with shadows below your nose and above your mouth. If the light's too soft, it will flatter your skin but you won't be able to see well enough to get your make-up right. If it's too bright, it will give you a ghostly pallor.

Put all the lights on different switches so you can alter the mood - for shaving you could use the lights round the mirror and a wall light but, when you're in the bath, just the wall light dimmed right down and a few candles.

If you have a period bathroom you can fit shades to wall-mounted fittings, but they must be approved for bathroom use.

Make sure you can see when you're in the shower with the cubicle door shut - try fitting a pressure-mounted waterproof light inside the door.

Lights specifically designed for underwater use, such as fibre optics, can look fantastic.