I've posted a few different ways I like to use origami in an EFL class (or pretty much any primary class). This is a fun one for primary students and I have found that it can be adapted to work with opposites quite well! (You could also do this with shapes, adjectives, rooms in the house etc.)
I posted about it a while ago at this link: http://eslcarissa.blogspot.com/2012/06/organized-opposites-orgami.html but some people had asked for a video. All the videos I've tried just haven't been very clear :( But I am still working on it.
Here is a graphic with pictures that may help.