If you are using a hard floor -- tape EVERY layer down -- I tape not just the corners, but every 12 inches all around.
If I have to do it on carpet, I use T pins -- the ones thay call upholstery pins. - again EVERY layer
Then I use safety pins every 6 inches all over. It does take extra time and effort but it really keeps the layers together. I hand quilt so you may want to baste the layers. When I do baste, I use a curved needle.
Mim