Your quilts are beautiful. I especially love the stained glass quilt.
I am working on Storm at Sea. There are 8 layers of fabric at some points. One of the suggestions to get it to lay completely flat was to trim the seam allowance of the darkest fabric close to the seam line. Not right next to it but just close. I didn't do it on one and I could really tell the difference. I had never seen that recommendation before but it works. I figure after it is quilted that the seams will not pull. I have pulled on the seams and it does not seem to affect the strength of the seam. I was concerned it would ravel.