I had only contracted a LA once in my life, and for that project I had a "project ticket" that she wrote that had just the basics on it ... the size of my quilt, the fact that I had supplied the batting, the estimated price, and the expected date of return. While I was there she deposited my top, backing, batting into a pillow case - folded over the top and pinned her copy of the ticket to secure it.
It did not mention the quilting design or the thread choice because I left both ENTIRELY in her hands after discussing several ideas.
If we had discussed specifics about the quilting/thread ... she probably would have included that on the ticket as well.