It'll help to find out the best filetype for print quality and ease of use, and stick with it.
My vinyl guy uses the older .EPS filetype, illustrator, freehand, signblazer, inkscapp are good vector programs to use.
Personally i think he needs to use better materials... But i don't complain i get then cheap lol.
As an installer... I really like 3M... And really dislike Avery... But cost is king