Worksheet and images of 4 paintings attached.

This lesson worked quite well for me - got the idea from Dave's esl cookbook. 
I stuck 2 of the colour prints at the back of the classroom and 2 at the front.  First I asked the students if they liked art and we discussed art for a bit.  They came up with the names of a few artists like Picasso and Van Gogh.
Then they went to look at each painting and brainstormed words.
My students don't have dictionaries so I told them they could use the computer to look up words. 
Then we went through each painting, writing the words on the board.  Next, I asked them to make sentences about each painting, writing some examples on the board - There is a cat with a human face, There are many stars in the sky, A ship is on the sea, etc.  Finally I asked them things like "Who is in the ship?" (ghosts, pirates ) and "Why did he give her flowers?" etc.