This is perhaps one of the most interesting parts of the design process. A key to a good garden design is in the handling of void & mass. Garden design is as much about handling space as handling the plants and structures that will form a physical presence (mass) in your garden. But dealing with the planting and other objects in your garden is tremendous fun and definitely not something to be taken lightly.
A good, cohesive garden design relies on an underlying pattern. Many Design Schools teach grid pattern to enable their students to devise plans where the overall scale has a relationship and the end result a feeling of unity, a feeling that the garden 'hangs together', and that makes the garden more satisfying to be in.
Some patterns are static. Think of a formal garden with its rectangles and squares forming a restful, static pattern. Other patterns can be flowing and suggest movement. Draw a curved path and then a straight one and you will see that the curving path suggests movement and that the other is 'still'. Thomas Church, an American designer who first introduced the kidney shaped swimming pool, and designed some striking and lovely dynamic gardens. Natural woodland gardens are more flowing in design, drawing you further into the garden.
The way the pattern is used, across or along the length of a space, affects the way you perceive it. The illustration (left) shows that a pattern that crosses your view makes the house seem closer than lines that run away from the viewer. Think of how you want to use pattern to create illusions of space, or distance, in the garden. In a small space you want to create an impression that the boundary is further away, but in along, narrow garden, emphasising the horizontal will make the garden seem wider and more spacious. Thus many of these gardens are divided in different sections or 'rooms'. A diagonal pattern is often used in small courtyard garden to emphasise the longest axis or dimension in a tiny space (below A and B both seem more spacious than the 'railroad' pattern in C)
Try out a number of patterns to determine those that appeal to you, and those that don't. You can try flowing patterns, static patterns and then try them horizontally, diagonally and vertically. And, remember, it's your garden. Then begin to imagine different elements of the pattern as different patterns of the garden: lawn, paving, planting, a pergola, pool, terrace etc. Make solid object a dark colour and leave open elements white. In this way you can begin to see the effect of 'void' and 'mass' on the garden.
Remember that, in the garden, you are designing in three dimensions. Your mass may seem far more imposing and dominating than in these patterns on paper. Too much 'void' and the garden will feel exposed and barren, but too much mass and it may feel claustrophobic and crowded (as in B above).
Using your tracing paper, fit a pattern you like over your measured garden drawing. Use a grid to ensure that the size of each part of the pattern relates to the other. Ensure that your pattern takes into account the current position of immovable objects (mass) e.g. your garage, swimming pool, kauri forest or compost bins!