Many people claiming to be photographers bring their cameras out on the sunniest of days. Not to say that sun is not a good thing, but truth be told, one can get beautiful  portraits of people in the soft diffused lighting of an overcast day. The soft lighting allows people to open their eyes and not squint. It creates a softer skin texture and less harsh shadows. Tools do exist for dealing with the harsh glaring sun but remember the many benefits of diffused lighting. Use your pop-up flash to add a little light and enhance the catchlight in yor subjects eyes. Frame the subject with the existing surroundings. Scrims and gobos are a good thing too! 

Hurry up, hit the shutter button! When they are ready, will you be? A good shot particularly when photographing people will be better if you take the picture fast. Make it easy on them. That pure moment will be captured and you will notice the difference immediately as you review the photos.  This fact is even more important when outside because the lighting changes fast. Sometimes I think some of my best work is captured after trying to get the perfect photo for awhile. The brain takes a rest and something greater than yourself takes over and there is it, the perfect shot.