A single light in the middle of the ceiling lights everything the same amount. Walls, sofa, floor and your face all get one flat wash from above, so there is no glow to settle into and no soft shadow to give the room depth. Most cosy rooms do the opposite: several small, low, warm lights that pool around where you actually sit.
Designers call this layering. You do not need all the layers, and you do not need to buy much. Often one extra lamp and a better bulb change an evening more than a new sofa would.
Kelvin (K) describes the colour of white light. Low numbers are warm and amber, high numbers are cool and blue. Old incandescent bulbs were around 2700 K and candle flames are lower still, roughly 1800–2000 K, so for evening living rooms people usually pick 2200–2700 K. Around 4000 K starts to look neutral like a shop, and 5000 K and up looks like daylight, which is great for a workbench and harsh on a sofa.
The practical trick: choose one colour temperature and use it in every lamp in the same room. Mixing a 2700 K lamp with a 4000 K ceiling light makes the warm one look yellowish and the room look patchy.
Brightness is measured in lumens, not watts. As a rough guide, an old 40 W bulb gave about 450 lumens and a 60 W bulb about 800. A lounge you mostly relax in is comfortable with far less light than a kitchen. Many guides suggest something in the range of 100–200 lumens per square metre for a general living room, but treat that as a ceiling, not a target: if you use several low lamps, each one can be 200–500 lumens and you will still feel the room glow.
A dimmer is the best upgrade of all, because the same lamp can be bright for tidying and low for the evening. Plug-in dimmers and dimmable smart bulbs work without touching any wiring. Anything that involves the ceiling light's fixed wiring is a job for an electrician.
Aim for light at three levels so the eye has somewhere to travel: something overhead (a ceiling light, kept dimmed or off), something at mid height beside seating (a floor lamp), and something low (a table lamp on a sideboard or a candle on the coffee table). Try keeping the brightest source below seated eye level, around 110 cm, so you are looking at a glow and not straight into a bulb. A shade that hides the bulb does most of that job for you.
Lamps are easy to get wrong because the plug and the floor are both fixed. Measure these before you order:
Two safety basics: leave space between a bulb and the shade (check the maximum wattage on the lamp), and keep candles well away from shades, curtains and anywhere pets could knock them over. Real flames are optional; LED candles give the same low glow.
Start with what you own. Switch off the ceiling light and move a bedside or desk lamp into the living room for a week. Swap the bulbs you already have for warm-white ones, all the same colour. Second-hand lamps are plentiful and cheap, and a new shade can refresh an old base. Buy only when a corner still feels dark after that.
Whichever you pick, put a warm 2200–2700 K, dimmable bulb in it. The bulb matters as much as the lamp.