For the past few years I have been doing "Free Professional Photoshoots" during my free time. It gives a chance to the families to have a photoshoot who otherwise wouldn't go out of their way to hire a photographer.
As shady as it might sound, the process starts from me posting an ad on Facebook or Craigslist. I usually mention that I will give priority to single parents, same sex couples or veterans. My favorite place to do shoots is right behind my office. The area is lush green during summer and makes for perfect background.
I love it when kids get excited looking at their photos in the camera. It's just a few hours for me to spend but it creates memories for these families that they will cherish for years to come.