Excessive Background Noise
From my experience, I have learned that the simpler a photograph is the better. By this I mean, when shooting a model you aim to have a background that compliments your model not compete with it. Let us consider a scenario in which you are to shoot a model in a cowboy costume. To complement the model you decide to shoot the session on a farm. You are faced up with two choices. In your first option, the model poses inside an old barn, with bails of straw and a couple of tools in the background. As a second choice, the model sits on a tractor with horses grazing in the backdrop.
You can realize that in the second instance there are too many things going on. The massiveness of the tractor and the moving horses are likely to overpower your model. On the contrary, inside the barn the background is not stealing the viewer's attention but rather it directs it towards the model.
Always keep in mind that your choice of background never overshadows your main subject; your model.
Have you ever tried to convey a message through your photos but the results said otherwise? One evening I received a call from a friend telling me that he had some great pictures that wanted to share with me. He said he had found this 'great' shooting location.
Upon seeing the photos I was terrified. The location looked more like a damping site than the country side he was trying to portrait. To be fair there was a beautiful pond surrounded by fantastic weeping willow trees, but the copious amount of damp scattered all over the area was a shame.
Do you sincerely thing that a glamorous shoot can be done in such a location? Such a situation could be termed as juxtaposition, meaning that the message conveyed would say that the model and the whole set is purely rubbish.
This kind of situation is observed in my magazines and newspapers, sometimes intentionally other times out of neglect or lack of knowledge. Keep your eyes wide open for these kinds of circumstances.
Conclusion
As you can see, in choosing the right background there is more than just colours, shapes and shades. It is a complex scenario in which conflicting details and complementary elements all play a part in your final product.