I am a longarmer and I use Sharon Schamber's technique. I am currently working on a quilt that is 90" X 90", so you know that could be a back breaker if I were pinning it on a table or on the floor.
I don't do anything on the floor since I have a dog that sheds and you know that could be a hairy situation no matter how well I clean.
I go to Sharon Shambers website for lots of helpful information. She is super!!! Here is her web address. She has lots of free information. You don't have to be a member for some of it; however becoming a member is well worth it.
Have a great day!
Jackie