I learned when and when not to use the lens hood. Yes, I already knew you need a lens hood when shooting in the afternoon sun to cut out lens flare, blah, blah, blah... Tonight I learned that it is not good to use a lens hood when shooting indoors with flash. It could block the built-in flash and it does not do anything to improve the image. Used outdoor on a bright day, however, a lens hood helps to cut out extraneous light which can reduce the contrast and sharpness of the image. With this insight, I am going to be more inclined to using the lens hood (outdoors) from now on.
The other useful lesson I learned tonight is something I think I have been sorely lacking. I think I have been fairly successful in taking pictures like portraits, flowers, and scenery. In looking through my Picasa gallery, I find that I have not attempted to take pictures that tell a story. My pictures "display" something (e.g. scenery or portraiture), but they don't "tell a story". Examples of telling a story are: humour (e.g. a pet and its owner dressed alike), mood (e.g. foggy scene), setting the scene (e.g. a market scene), symbolism (e.g. a priest with a rosary), and theme (e.g. flower pot on window sill, reflections, etc). This lesson is the impetus I need when I am low on inspiration.