Ponds have a wonderful ability to create an illusion of space. If you have a small garden place a pond at ground level in the foreground of the garden, with the longest part of the pond following the longest length of the garden. This will ‘force’ one’s eyes to move down the length of the garden and make the garden appear bigger.
A well-placed mirror in a garden can also create depth and dimension, especially in small spaces. Ideal spots for placing a mirror would be at the back of a pergola, behind a garden arch, near a pond (to reflect the water) or on a boundary or courtyard wall. Disguise the mirror by edging it with wooden trellis and growing a creeper on the trellis. Lead foil mirrors are best for outdoors and using a waterproof sealer will minimise weather damage. Avoid placing mirrors where they will reflect direct sunlight as this can be very annoying.