Originally Posted by feline fanatic

I would not recommend using embroidery stitches for quilting unless it is a simple running stitch like Sashiko which essentially is the quilting stitch and used quite a bit in big stitch quilting. I think a stem stitch would overpower your piecing if used as a quilting stitch, especially if you use a heavy perle cotton thread or floss. Also many embroidery stitches are not meant to be viewed from the back and some of them aren't very pretty from the backside. Remember that your stitches show on the back as well as the front. And one last thing to mention, with embroidery stitches you are going through a single layer of fabric or maybe a couple of layers if you are embellishing applique. The embroidery stitches you are very comfortable with may become very uncomfortable when trying to do them through multiple layers of fabric (when you go over seam allowances) and batting. I would think it would quickly become an effort in frustration.

Just use a regular hand quilting thread and go for it. No one will ever notice that your stitches aren't all perfect or the same length, including you, once the piece is completed. What you view as imperfect when you are working on it and viewing it from inches away won't be noticeable once the piece is completed and viewed from a normal distance of a couple of feet. The only way you will get good at hand quilting is to just do it. Don't be afraid to mark your topper so you have lines to follow or use masking tape. You can also use the tiger tape that juliasb mentioned but I never did. I did use 1/4" masking tape a lot to quilt 1/4" away from my seams.