One of the important thing i can think of is, continuously work on enhancing his language all the time. Not necessarily during lessons time and so on, whenever there is any opportunity, enhance the language. Of course, we need to get alot of things about him more right first in order to help on the language part, the focus, etc.

With language, I feel its one of the main area holding back an autistic kid in socializing.

If you are able the books "The Verbal Behavior Approach", "RDI activities for young children" and looking into "Social Thinking" are things I would suggest... great sites if you are able to access are understood.org and behaviordoctor.org

Daily chores
Generalization of things
Socialization
Games

What skills are you working on?