Light - both natural and unnatural - has a huge effect on the atmosphere and aesthetics of each room. Let's look at both types of lighting and see how we might improve our homes using light.
Daytime - Natural Light
Natural light can really flatter a room and make it much more pleasant to be in. The natural light of any given room depends on its windows, which way people face when spending time in the room, and possibly how open plan the house is. Of course, windows are the biggest influence: how big they are, what direction they face, what obstacles are immediately outside the window (if any), and what obstacles block the window inside the room. This article is only going to cover quick(ish) fixes, so we're not suggesting you knock out walls or anything extreme, but you should consider how wide curtain rails cover the window and whether you can extend those if the curtains are blocking part of the window even when full pulled back. You might also consider outside obstacles to light, such as the height of a hedge of branches of a tree. Having said that, you also need to consider that excess light in warmer months can make a room very hot. Consider thick curtains if you do live in a hot climate - not that you would draw the curtains when you're in the room (air conditioning would be more suitable), but if you're out for the afternoon, drawing thick curtains can really help keep the room cool for when you return.
Nighttime - Lighting Options
This is the time of day where you have a lot more creativity when it comes to lighting. Soft spotlighting (table lamps, spotlights) can really soften the atmosphere while giving the utility of a well-lit room. Avoid large, bright ceiling lights (strip, or bright light bulbs) if possible - these have utility, but they can make a room seem a bit drab, if not outright harsh. Lighting with dimmer options are great as you can really have that granular control over how much lighting you wish to have for the room.