I use fast frames for my Brother PR600II. I have used them for years.
I attach the main frame to my machine, then prepare the specific size frame I need.
Depending on the project, I choose what I would normally use for stabilizer and go. It is my preference to cut the stabilizer on the individual hoop, (4x4, 5x7, etc). Once cut I use Crayola glue stick on the back of the frame, apply my stabilizer, flip the whole thing over and put my fabric where it needs to be, clip the fabric on, and go.
Please send me an email if you want more info or tips.
bnilla9241@aol.com
Hope this helps hugs, Bonnie