The pool itself should be orientated as much as possible in regards to the sun and the best surrounding views.
This means that, typically, the afternoon sunshine should be coming from the west, and not at their backs. There are, of course, numerous variances on this, since it depends largely on how the home is situated. If the home faces west, for instance, the pool being typically at the rear of the home will have the most open space facing east.
Whenever possible, there should always be a deck area at the pool’s northeast or northwest corner (depending on the region of the country and angle of the sun) to take advantage of afternoon sunlight reflecting off the pool’s surface.
Keep in mind that the sun angle swings widely over the course of the year.