So, the first thing I did was put my folding table on bed risers. This will raise it to more of a counter height and will help you from bending over as much. Shorter people might not need the bed risers. I've seen people use lengths of PVC pipe too, but bed risers work really well.
Lay out your backing on the large table, right side down. Make sure the backing is flat, but not stretched. Secure with binder clips, or masking tape if your top isn't too big. There are a few minor waves in this photo, but nothing that will cause a pleat in your quilt.
And that's it! I usually flip the quilt over to the back side and smooth out the backing one more time. All of the clipping and unclipping can make things shift, and it will help the temporary adhesive adhere better anyway. On to quilting!