I am reading Mary Mashuta's book Foolproof Machine Quilting:
http://www.amazon.com/Foolproof-Mach...509789&sr=8-11 She does not recommend marking a quilt but suggests other methods of marking (like tracing a template onto shelf paper and sticking that onto the quilt top to stitch around). I did my first ever machine stitched "star" using this method and it turned out great.
In addition to using the template/shelf paper method I also use a Heramarker and painter's tape for straighter line stitching or cross-hatching.
Anyway, that's my 2 cents....