The height of the retaining wall will affect the visual image of your property. A single tall wall with the yard level on the same plane as the house will give your garden a formal upright look. A single low wall with the yard sloping away from the house provides a more relaxed look to the garden. Using more than one retaining wall to make tiers coming down from the side of a house creates a whimsical look.
The shape of the retaining wall adds character to the yard. A retaining wall does not have to follow the lot line. Straight and boxlike retaining walls give a formal look to the garden. A rounded edge to the wall will produce a softer look. A curvilinear retaining wall will give an informal look to the yard.
Retaining walls are made out of a variety of materials. Repeating material used on the home exterior presents a tidy look; a brick retaining wall with a brick house is a formal and unified look. Flagstone is used as accent trim on some homes and is a good material for building retaining walls. Not all exterior house materials will work as material for a retaining wall. Vinyl siding and stucco are examples of materials that will not work. In those cases, choose a natural material, like landscape timbers or field stone, to build your wall.
The color of the retaining wall should be neutral or complimentary to the color of the house. The retaining wall should blend into the landscape, not stand out. Avoid bright colors. The visual focus is the house and garden, not the wall.