I agree, it sounds like you probably need to loosen your top tension. Try loosening it a little at a time until you see improvement. And I also use a larger needle, preferably a 16/100. I sometimes use a top-stitching needle (it will say on the pkg), depends on the thread I am using. It always helps to do a practice sandwich of the exact fabric, thread and batting you will be quilting on because all of these can affect the way the stitches look as well. Also, depending on your machine, make sure the feed dogs are down. Although some folks do seem to FMQ just fine with them up.