sounds like it was a successful first run! Congratulations! I haven't had a quilt on my long arm for about a year and wondering how I will do. I usually try and have about 3-4 extra inches of backing and batting on each of the four sides. The thicker the batting, the more fabric seems to be eaten up while quilting. I also like a little extra width on the backing and batting so I can place a piece of scrap fabric down one side to check my tension on.