When I am hand piecing, I sew kinda "around" the seam..well, I mean I don't sew it down either direction. It can kinda "float" back there until I get ready to do my final ironing before I sandwich the quilt. That way, I have more flexibility and I am not trying to sew through so many layers. It hurts my fingers. I sew up to the seam, take 1 stitch on one side of the seam, pass the thread through the seam on the back, then 1 stitch to lock it on the other side, then off I go again!
Clear as mud right?