I have a couple of the square rulers...12.5", 6.5" and 4.5". I use those when I am squaring a wonky block. I find I don't lose near as much that way. Just shave a little here and there to even it up. I tend to make the blocks/pieces a little bigger and trim as I go. For example, if I'm using 4.5" half square triangles, the directions usually say to start with 4 7/8" squares, but I start with 5" squares and then trim the hst to 4.5" when I'm finished with it. Like Rose Marie says, I think that is what Eleanor Burns does. When I first started quilting I was always "losing" my points until I started doing this.