Is this going to be modern day?
As a lot of the slang has changed over the years.
If they are going to be modern day chav (or charvers,as we call them in the NE) teenagers,use the word "how"
as much as possible,and all word finishing in "er" replace the "er" with an "ah".
eg."How mista,your car is pure beltah,how."
Hope that has been of some help.
