Christy
Starts/stops are one of those things that the best advise is ... practice, practice, practice. At that point you have to take a deep breath, position your hands and make sure the quilt is position exactly as you want it so when you *go* ... it goes in the right direction (be that forward, backward, or sideways). Think about where the needle is positioned and facing, and think about the immediate direction you want to go.
My best advice is to keep practicing stops/starts on scraps. Build a bunch of scrap sandwiches (I like making 9" pot holders with quilt pattern *tests*). Your quilt isn't the place to develop new skills, so think about putting it away and practicing until you are comfortable with stopping and starting a curve.
Practice using the hand wheel to start your machine a stitch while gently pressing the foot pedal. The slower starts may help. Once you have that down, practice using the foot pedal only.
Practice starting in different directions. You may find that it's easier to start by moving the fabric forward than it is to move the fabric toward you or to the side. After a while ... it won't make a difference.
Good luck!