JanRN,
I'm no Y seam expert, but this is what helped me. You can click on the pictures in the tutorial to make them bigger and easy to see.
I don't press my seams open and I don't pivot. I take a couple of tiny back stitches and remove the piece from the machine. I fold fabric out of the way. Then I line up the next seam. I use starch on the pieces to keep them from stretching. I hope this tutorial helps.
Janie
http://how-to-quilt.com/articles/220...t-in-seams.php