Most rooms are lit the way an office is lit: a single bright fixture in the middle of the ceiling, casting a flat, shadowless light down onto everything equally. It is efficient, it is even, and it is almost entirely wrong for a home. The rooms we most love to be in are never lit that way. They are lit in layers, with pools of warm light at the height we live at, and learning to light a room the way you actually live in it is one of the cheapest and most transformative things you can do to a space.

The problem with the single overhead light is that it flattens. It erases the shadows that give a room depth, it lights the tops of everyone's heads unflatteringly, and it treats a corner you want to feel cosy exactly the same as the middle of the floor. A room lit from a single high point has no places to rest the eye, no sense of intimacy, no variation. It is bright, and brightness is not the same as good light. What a living space wants is not more light but better-placed light, and less of it than you think.

The principle that fixes almost everything is layering, which simply means lighting a room from several sources at several heights rather than one source from above. Think of it in three loose layers. Ambient light is the general fill that lets you move safely through a space. Task light is aimed where you need to see — the reading chair, the kitchen counter, the desk. And accent light is the quiet layer that gives a room its mood, the lamp in the corner, the glow that washes a wall. A well-lit room has all three, and rarely needs the ceiling light on at all once the sun goes down.

Height is the second secret, and it is where most homes go wrong even when they own enough lamps. Light that comes from around the height at which you sit and stand — table lamps, floor lamps, wall lights — feels warm and human, because it lights faces and surfaces the way firelight and candlelight always did. Light that comes from high above feels institutional, because almost the only places we experience overhead light are institutions. Bring the light down to living height and a room relaxes instantly, even with the same total brightness. A pair of table lamps will do more for a living room than the brightest ceiling fixture ever could.

Warmth of colour matters as much as position, and it is worth being fussy about. Light has a temperature, measured in kelvin, and the cooler, bluer light that suits a workspace is actively unpleasant in a place you want to unwind. For a living room or bedroom, choose warm bulbs, around 2,700 kelvin, the colour of a low incandescent or a candle. Mixing warm and cool light in one room is jarring, so keep the temperature consistent across your lamps. And put as much of it as you can on dimmers, because the single greatest lighting upgrade in most homes is simply the ability to turn the light down as the evening goes on.

Then light for the specific things you do, not for the room in the abstract. Where do you read? Put a directional light there, over your shoulder, bright enough for the page and nowhere else. Where do you eat? Hang a light low over the table so it pools on the food and the faces around it rather than filling the whole room. Where do you want to feel cosy on a dark evening? Put a small, low lamp there and let the rest of the room fall into soft shadow. Good lighting is not uniform; it is a landscape of brighter and darker places that follows the shape of your life.

You do not need an electrician or a renovation to do any of this. You need a few lamps at living height, warm bulbs in all of them, a dimmer or two, and the willingness to leave the big ceiling light switched off most of the time. Start by turning it off tonight and lighting the room only with lamps, and notice how different the space feels — softer, deeper, more like somewhere you want to stay. That is the difference between a room that is lit and a room that is lit to be lived in, and it is almost entirely within your reach.