When ripping out a seam, you know how you often wish you had a third hand? One hand to hold one side of the seam allowance, one to hold the other (with gentle tension to separate the two layers) and one hand to hold the seam ripper. And it is true that there are gadgets made to provide this extra grip: I even own one, a metal "bird" with several clamps to hold the fabric. That tool is usually buried in the drawer and, though heavy, it slides around unless anchored to a table top.
What Gretchen did was to sit at the sewing machine and place one seam allowance under the lowered presser foot. The foot becomes your third hand! And the sewing machine is right there, heavy as can be and even providing its own lighting.
I'm down a hand in this view, since I needed my right one to snap the picture. The right hand would normally hold the seam ripper...or the razor blade.
Do you know about the razor blade? That's a great tip, too. Sometimes a seam ripper is still best, but much of the time I use a naked blade to make quick work of seams that must be opened.
So as I thought gratefully of Gretchen's helpful example, it occurred to me that you, like me, might never have seen or thought of this trick either.
Now you have!