pay attention to the background! every tree, car, person, etc... can distract from the overall appeal of the portraits you take. avoid having trees come out of heads and make sure that any other object in the background doesn't break up the space in a weird way. a simple background almost makes the background disappear and helps to bring the focus on to the subjects of your photographs! a good background is never irrelevant, but it never needs to be the focus of the image.
so when you look through your camera, don't just try and capture that perfect expression (although you're going to want to do that too), first look at what is happening behind and around the person you're photographing and move, if needed, to a new angle to improve your shot!
here are a few shots from last year's memorial day festivities of my little boy. how he has grown! he's pictured with his second cousin. what cute guys!!