Besides being beautiful, a landscape design must first and foremost be useful for the owner. It has to serve a practical purpose to be truly effective. For example, some designers employ tall hedges to provide privacy for the people in the home.
These same hedges also serve as protection from the sun to keep your house cool naturally, lowering your overall air-conditioning and electricity bills in the process. You can also browse to http://royallandscapes.net/ get more information about landscape design.
Landscape design can also be used as a pathway to give your guest a pleasant trip to your front door. Finally, a useful and beautiful design will not be worth it if you have no way of sustaining it. It would not be practical to build a tropical garden if you live in the middle of a desert.
Much the same way, why would you build a garden full of succulents when you live in a tropical country experiencing constant rains? It takes money to sustain a good landscape design and as such, it would be wise to work with nature instead of against it.
When hiring a designer, try to look for a design that complements the weather and materials available in your region. By doing so, you not only minimize the costs of building the design but the costs needed to maintain them as well.