A good, flexible rule for settling the main shapes of the subject is to have a good foreground, a middle distance and then the background.
It is easy to ignore the foreground and only look at the middle or background. Because our eyes take in a scene so rapidly we take the foreground for granted and concentrate only on the view, that is, the background. In sketching one must be careful not to do this.
A good piece of foreground will give space and distance to your background. Leave it out and the picture will look flat. Also, if we only concentrate on the background, we will not be able to distinguish the different shapes and colors properly, or the details. It is a strain on the eyes to do so. So if you want to draw something with great wealth of detail in it, and wish to avoid eyestrain, get up closer to it. Your eyes are not magnifying lenses. Don't treat them as if they were. If it is the background, leave it there. If you want to see more of it, get up close and make it into the foreground.
Better still, always have, if possible, those three things in this order: foreground, middle and background, in everything you do. You will be surprised how convincing it will make your sketch (Fig. 20).
BIG AND LITTLE
The eyes take in too much. They see the small shapes first; the details of a scene are recognized more quickly than the large overall shapes. To start off a drawing by putting all the little things first will lead you into all sorts of muddle and make you discouraged too quickly. Better to lay in, with a light wash, all the large shapes and then, if you want, put in all the detail after it has dried. I have seen this method of working in practice and can recommend it. However detail-conscious you may be, this way won't lead you into any trouble.
Going for the large shapes first is very important. Your viewfinder will help you in this. Trees, for instance, consist of tiny units that make up the character of the tree. Plot this large shape first and you will be less likely to miss the character. A wall, too, is made up of tiny shapes. Get the shape as a whole first; leave the bricks till last. This applies to all things. First grasp the large shapes, relating them to one another boldly and lightly, then reinforce them with the detail, the small shapes, later.
This applies to painting or drawing and I cannot stress it strongly enough. In time, with experience, you will be able to recognize the large shapes quite naturally. But at first be very careful to make allowance for them.