The tip, "Three Pins for Bulk," was actually intended for achieving perfectly aligned triangle points, but I somehow managed to misread or misremember it to be a tip for achieving perfectly matched seams (when piecing nine patch squares, for example). Usually, I line up seams by butting one seam allowance up against another, like so . . .
However, this technique can't be used if the seams are not pressed in opposite directions, or if the seams are ironed open. So, undoubtedly, when I first read this tip a little light bulb must have gone off over my head. "Ah-ha! I can do this to match up seams too!"
While recently piecing quilt squares in which I would need to match up diagonal seams (ironed open), the misremembered tip sprang to mind. This is how I remembered the tip: insert a pin directly through the center of both seams to line them up, insert a pin on either side of the first pin, remove the original pin. I don't like to pin any more than absolutely necessary, so this is how I left it . . .
How did it turn out? Well, of course, I achieved a perfect point on the very first try.
Eureka! Before I got too excited, though, I thought I better try it again. Would the results be consistent? Nope. I got a consistent result, but not the one I wanted. About three points were perfect, and the rest were off a tiny bit--like this one . . .
I tried again, inserting the two pins I originally omitted to see if it would make a difference, but the result was the same as above. On the other hand, I was using a slant shank machine for which I don't have a walking foot. Would this technique be more consistently successful using a walking foot? I would think so, but I haven't returned to this project yet. I'll keep you posted. For now, though, I'm not too worried about it. I doubt the recipient of this quilt will be examining it this closely. What's your tip for perfect points, and/or perfectly matching seams?