Art Therapy/Class for Autism/High Functioning Aspergers!

Hello everryone!
I was wondering if anyone could help me out!
I have worked as the art "teacher" at my summer camp for children with Asperger's or High Funcitoning Aspergers for the past 2 years.
I have not necessarily "taught" these children, but instead provided them with numerous art supplies and prompted them with suggestions/ideas/etc.
It has worked wonderfully and many of the chidlren are able to create amazing things.
I was recently hired to work year round for their academic semesters program and am hoping to do more one-on-one or small group activities.
I was wondering if anyone had any ideas for openers to use with a small group of children with Asperger's or Autism (the kids range in age from 10-16 and i would be with either 1 child at a time-but could have up to 8 kids)

sorry the message is so long.. but i would really appreciate any feedback that is possible! thank you!
~PennY LanE