An idea to encourage abstraction to help your students along. This works
best with older students.
Collaborate with an English teacher, or get them to do this yourself.
Ask your students to write a poem that likens them to an animal,
vegetable or flower. A piece of furniture, equipment or useful item, in
fact, almost anything non human. Once they have done the poem, get them
to illustrate it.
You can sometimes gain the most amazing insights into their self images
using this method.
Hope it helps