I'm not sure if this qualifies as worst advice or even bad advice but I've never heard this before. I was looking at one of my first quilt how to books (I think it is Better Homes and Gardens even) and it instructs you to press from the back (not locking in the seam, or pressing the seam open, but the pressing the seam to one side). I have tried this the past 2 days on little 4 patch and 9 patches I am working on and it seems to be working okay. In the next few days I am going to see if this helps with stretching the fabric--especially when doing little strips like one inch strip sets. Bad advice, I don't know yet???