I clip all the stray threads on the quilt top back. I iron and starch my top. I lay it flat out on the floor to check for any ripples in the border. If a border has ripples, it should be fixed before it goes to the long armer because they can only quilt out so much extra fullness in a quilt edge. If everything lays nice and flat, I use my large 15 inch quilter's square in all the corners to make sure the top is square. I trim the top if necessary being careful there is still 1/4 inch seam allowance all around the quilt for the binding.