So, lets talk about some of the things you should consider when designing your landscaping, based on the type of region you live in:

Temperate Region

 Maximize warming effects of the sun in the winter.
 Maximize shade during the summer.
 Deflect winter winds away from buildings.
 Funnel summer breezes toward the home.

If you can get your landscaping to do these four things, you will find it invaluable. These things can be accomplished by planting deciduous trees with lots of coverage. The trees will provide maximum shade in the summer, but will lose their leaves to allow the sun to warm the house in the winter. By planting rows of shrubs or trees that act as wind breakers you can also deflect winds from the buildings, and keep those nice summer breezes directed.

Hot-Arid Region

 Provide shade to cool roofs, walls, and windows.
 Allow summer winds to access naturally cooled homes.
 Block or deflect winds away from air-conditioned homes.
If you live in a hot arid region you want your landscaping to make your outdoor spaces more comfortable, so planting trees that provide shade, and shrubs etc to block the hot winds from heating the house will make your life much more comfortable.

Hot-Humid Region

 Channel summer breezes toward the home.
 Maximize summer shade with trees that still allow penetration of low-angle winter sun.
 Avoid locating planting beds close to the home if they require frequent watering.
Your landscaping will really make your home more comfortable if you think through it properly. Plant taller trees that provide shade you need in summer, but that are high enough to allow the sun to penetrate the areas in the winter. Direct the breezes by creating wind breaks etc. that will channel the breezes to your home and cool your home naturally.

Cool Region

 Use dense windbreaks to protect the home from cold winter winds.
 Allow the winter sun to reach south-facing windows.
 Shade south and west windows and walls from the direct summer sun, if summer overheating is a problem.

Planting windbreaks is essential to accomplishing these landscaping goals. For maximum protection, plant your windbreak at a distance from your home of two to five times the mature height of the trees. The best windbreaks block wind close to the ground by using trees and shrubs that have low crowns. Dense evergreen trees and shrubs planted to the north and northwest of the home are the most common type of windbreak. Trees, bushes, and shrubs are often planted together to block or impede wind from ground level to the tree tops.
Basically, to get the best landscaping possible you need to consider your region, climate, and conditions, what plants grow best in those conditions, and how you can use those plants to your advantage to cool and heat the areas you want cooled and heated, and to provide protection that allows your yard to be used for fun!