Positioning a backyard awning to provide the most shade depends on the configuration of the yard, the presence of any tree coverage and the time of day during which you want to have optimal coverage. Some configurations allow for larger amounts of shade during specific times of day, while others offer a general level of consistent coverage in standard conditions.
Begin by surveying the backyard to determine the area that needs the coverage, such as an attached patio or an open section with seating, as this heavily influences the awning design. You also need to decide when you want optimal shade, as the sun changes position during the day creating different shading conditions. When the sun is rising or setting, it creates significantly more shade than when it is directly overhead, which is also when the sun tends to be the hottest.
If you want a general amount of shade, create a flat awning that sits directly above the coverage area, supporting it with polls at its perimeter. It may also be possible to angle the awning upwards if the area sits near the home, which also helps to reduce rain and leaf build up. Another options is to use a flat awning that has an additional angled overhang or drop-down section for use during rising and setting suns. Alternately, some combination angled configurations allow for high amounts of shade during all sun periods, as long as the high points direct towards the setting and rising sun.