Get off the beaten path
While the main areas of the parks are well traveled, there are many areas that guest seldom visit. Most of these areas provide fun and unique photo opportunities.
Capture the moment
Posing for icon shots are a must, but also try to capture fleeting moments. A Disney vacation is about experience and creating memories. When you look back at all your pictures later, you are more likely to remember what you were feeling in these moments rather than what you were feeling taking the icon shot - which is probably "I wish my parents didn't make us take so many pictures" or "I wish my kids would stop complaining about taking icon shots".
Be part of the memories
Being the one carrying the camera, you tend to be the "designated photographer". One great tip is to use Disney's Photopass Service so you can be in the pictures. But even without photopass, make sure to get in the photos as well.