Comparing and contrasting is one of the essential language functions that students of ESL and other languages are expected to master.  

You have the graphic organizers; you have taught your students the glue and mortar (ie the grammatical structure and phrases) in place to help them connect their ideas and find similarities and differences; you have probably assigned an essay to compare and contrast, say, lions and hyenas, and you may even be pleased with the results. 

Here is another resource to consider for your compare and contrast toolbox: