Composition - do's and don'ts
Composition of a painting is the selection of shapes, colours, tonal values, textures etc. and how they are placed in a painting. There are basic rules to composition, but at sometime they have all been challenged and broken by the great masters.
As a beginner it is best to learn and be guided by the rules, you can experiment with breaking them when you gain more confidence.

Firstly consider the format of your paper. A square is solid but also very static, the eye concentrates on the centre and is reluctant to explore the rest of the space, therefore careful placement of the focal point of the subject must be considered. This format is really only useful for tight intimate themes.
In portrait format (so called because it is the classic shape used for portraits) the painting can appear unstable as if it will topple over. However with careful use it can be used for scenes other than portraits, for example with a strong solid foreground to anchor it.
In the classic landscape format the paper appears much more solid and lends itself well to panoramic scenes. The eye is more willing to wander around.
Contrast is an important issue. Having decided on the format you will need to consider what to put in and what to leave out of a picture, you should also think about some contrast within it to balance the painting.
In this quick painting contrast was formed with the use of colour, the splashes of orange against the flowers. Shape was also considered with the geometric pattern of the cloth against the organic shapes of the flowers. The painting has a light bright atmosphere to it created with the dark tonal value of the cloth. The strength of the cloth also anchors the painting giving the format more stability. However the central placement of the vase is not so pleasing to the eye, we are drawn to the centre of the flowers and are less inclined to explore the whole of the picture.
Further considerations not included in the painting above is the contrast of textures and mood. For example in a seascape it might be the solid craggy rocks against the smooth ever moving ocean creating textural contrast. A painting with a lot of energy and movement will need some part of it to be tranquil as a resting place for the eyes.
In summary then, contrast can be formed with the use of shape, colour, tonal value, mood and textures. A good painting requires some contrast but not necessarily all of these. With experience you will begin to see what makes a good painting for yourself.
The placement of the components of your painting also have to be borne in mind. Here we consider 'the rule of thirds'

The above diagram shows a paper divided into three both horizontally and vertically. A horizon should be placed on one of the red lines allowing either the sky or the land to dominate. The focal point of your subject should be centred at one intersection where the blue lines cross the red ones i.e.. at the green spot. Again if focal points or horizons are placed centrally the painting will appear static and the eye will refuse to explore the rest of the image.
Next consider the objects in your scene. It is easy to lead the viewer astray. to avoid this there are a few simple rules.
If there is a path, road or river the eye will travel along them and if you are not careful out of the picture altogether. To combat this, block the view by placing some obstacle in the way such as a tree or a figure facing back into the image.
Figures, animals and modes of transport should always face into the picture towards the focal point encouraging the viewer to do the same.
Likewise straight lines from a roof or a fence should indicate towards the focal point.
Whilst we are on the subject of fences, walls and other solid objects don't paint them right across the page, they will act as a barrier forbidding the viewer to look beyond. Instead leave a gate open and invite them into your scene.
Your focal point should be dominant in a scene. If for example you are painting cows in a field the focal one should be the largest and clearest with others much smaller and further, away as support rather than fighting for the viewers attention. This will result in more balance.
On the subject of balance if the scene has a dark mass of land or whatever this too should be balanced with a dark cloud in the sky. Think of tonal mass and detail as sitting on an old weighing scale, they look awfully ungainly until they are nearer to level.
The focal point should also hold the greatest contrast in the picture, light against dark or complimentary colours.
Link objects together wherever possible, place the tree so that it or the house overlaps a little. But beware where unrelated lines appear on the same level. For example if you are working from a photograph and the top of the roof coincides with the hillside beyond as in the first picture below it is better and more interesting for the viewer if their is a little remodelling as suggested by the following images.
Beware of symmetrical shapes. Especially when they are repeated among the scene. In a conifer forest make some of the trees lob sided, not just a collection of neat triangles.
Having now some knowledge of correct composition visit your local art gallery or take a look at books or the world wide web. Using tracing paper discover how the great masters used composition in their work and how sometimes they broke the rules.
Copyright Jane Grainger 2004