Does your living room need a facelift? No need to spend thousands of pounds on a new expensive furniture set -- just head on down to your local DIY outlet and grab yourself some paint. Painting the walls is one of the easiest, least expensive ways to give any room a completely new look. With some old jeans and a little elbow grease, anyone can slap on a new coat of "Eggshell White" or "Tropical Rain." In fact, painting is so simple that the hardest part of the whole process might be choosing the right colour.

The walls you paint are a small part in a much larger story. What else is in the living room? Do you already have a bookcase you love? A couch you can't get rid of? Take all of that into account. Before abruptly changing the entire atmosphere of your room, take the time to think about what colours you'd like with which pieces.

Look at the natural light in the room at different points throughout the day. Pay attention to how it interacts with the space and where any shadows might fall.

Cool colours -- blues and greens -- make a room feel cooler and calmer, and remind us of nature. Reds, yellows and other sunny colours create a sense of energy and movement, and make the room feel physically warmer.

Related: Hello, Yellow: 5 ideas to brighten a room

Do you have a tiny, odd-shaped room? Go for the pastels and whites. Lighter colours make a room seem larger because they "recede" from the viewer. Darker colours are ideal for larger room, or where you’re trying to create a cosy feel, because they "advance" and appear to come toward you.

Start collecting ideas and things that inspire you. Gather photos from magazines or design blogs and organise them into folders on your computer or a binder.

Select paint samples from a DIY or paint shop that match your favourite colours from the idea book. If possible, gather the larger paint chips as this will make your next few steps easier.

Related: The psychology of colour: What your home's colours say about you

Get a feeling for how the paint will mesh with the parts of the room you already have in place. Check the samples against flooring, existing furnishings and artwork.

Many DIY outlets sell small paint samples in pints. This way you can pick a few favourite shades, grab the samples and test them on your wall before committing to a larger can. When you see the paint on the wall, you'll get a better feeling for how it will look and in that particular lighting.

Wait a week before deciding on a final colour. Look at the colours under different lighting and at different times during the day. After living with these looks for a week, you'll have a better idea of what you'll love long-term.