Preliminary requirements

Before deciding to purchase an artwork from a gallery or direct from the artist, make sure the artist used high quality paint and not inferior student quality pigment. 

Artist quality paints will not fade readily and are more stable unlike cheap household paints and student grade pigments. Unfortunately, many emerging and "self-declared" artists use inferior materials, including canvas, stretcher bars and paint and unsuitable yellowing varnish. In the case of digital prints, they may not use pigmented inks and acid-free paper, but dye based inks which fade quite quickly.

Avoid experimental mediums such as bitumen and like, I have seen many artworks self-destruct over time where the "artist" experimented with unproven methods and materials including non-archival materials.

Selecting artworks

Look at all available paintings and sculptures in the gallery or artist studio and assess the artwork's suitability for their intended location.  However, when selecting a piece do not rely entirely on intellectual reasoning and logic, but listen to your gut feeling and intuition.

An artwork should "speak" to you, capture your attention and get you emotionally moved. Recognise this and follow your desire and instinct.

If you and your partner cannot agree on an artwork, consider having a "his and hers" purchase, ie each of you choosing a piece really really liked, rather than a middle of the road compromise.

Always choose enjoyment over investment considerations unless your main interest is just to make a profit.

Hang paintings in living areas instead of mirrors

Instead of mirrors and such "lacking in personality" items, consider hanging paintings or bas-relief wall sculptures on your walls .  When you have mirrors in living areas (as opposed to bathrooms and dressing rooms) why would you want to look just at your own reflection all the time when you could enjoy  an artwork instead.  You might be very pretty and impressive, but ... really, stop being narcissistic and be serious!?

Advice on hanging paintings

Do not try to match colours in a painting to your cushion or curtain. This pedestrian approach will ignore or minimise any artistic merit an artwork may offer.  Most paintings and sculptures have a life of their own and do not need to harmonise with an existing interior design colour scheme. 

It is important though that there is no significant clash with existing dominant colours in the room but a certain amount of contrast may be acceptable and beneficial. Like jewellery provides accent to an otherwise harmonious outfit.

Do not place a small painting on a large wall. Be brave and choose a decent size artwork on a given wall space that creates an impact and improves your visual environment.

Do not hang paintings too high, ie the centre line of the painting too far above the eye level of an average height woman.

Don't be afraid to buy a non-cliché painting, ie a highly original piece different from the run-of-the-mill ordinary stuff.  Many galleries promote pigeon-holed, mass produced works, where a successful artist is encouraged to turn out paintings in the same style over and over.  The sense of adventure and the thrill of discovery and the magic of freshness may be missing from such works.

Give preference to galleries and artists who have a satisfactory return and refund policy.  This is important in case you are not entirely satisfied with your purchase.

If you own a number of paintings, try to rotate them between rooms and available wall spaces.  You will be surprised how a painting can assume a new lease of life in a new location.  It is like a holiday for pictures and for you like a pleasant meeting of an old friend.