Mr. O'Brien (our reading teacher/consultant) and I had a discussion about how details are an important part of reading, writing and art. I learned from him I could use some of the same vocabulary that the kids use when learning about reading and writing and apply it to what the kids are learning in art.
We read a book called Little Robots. The book has wonderful illustrations of a variety of robots. I asked the kids to analyze the illustrations and tell me what "details" made the robots look like robots instead of people. They came up with a huge list. Some had screws, antennae, metallic colors, light bulb ears, lines where they bend their arms and legs, etc.
I taught the kids how artists use highlights/reflections and shadows to make an object look 3-dimensional. We painted the basic shapes of the robot bodies and added the highlights and shadows. Then the kids created their own details based on the ideas they generated from the Little Robot book.
Their robot paintings have a realism and richness to them because the kids embellished them with many details.