You might not realise you've got bad lighting but you'll recognise the symptoms: headaches and sore eyes, frustration in the kitchen at not being able to see what you're doing and arguments in the bedroom over whose turn it is to get up to switch out the light. Good lighting will make your home feel spacious, clean and welcoming.

North facing: cold and harsh rather than direct sunlight. Artists choose north-facing studios because the light gives truer colour rendition.
East facing: bright first thing in the morning followed by long shadows and no sun later in the day. Use artificial lighting to control glare and maximise the available natural light in north- and east-facing rooms.
South facing: warm light all day, although it changes throughout the day and year. The midday sun is usually so bright it flattens everything out. Choose south-facing rooms for the kitchen, main living areas and other rooms you spend a lot of time in.
West facing: sunlight at the hottest part of the day, which can cause glare. In the late afternoon, you'll get long shadows and softer light.