1. Feed dogs down.
2. Stitch length at zero.
3. Use hopping/quilting/darning foot.
3. Wear Machingers gloves.
4. Change presser foot pressure to lightest possible if you can make this adjustment on your machine.
5. Be sure to have presser foot lever DOWN when you stitch with your quilting foot. Easy to forget this step but it may explain all your problems.
6. Practice on sandwiches made with backing, batting and top fabric. Mark these with designs you want to follow using an air-soluble marking pen. When the marks disappear in a day or sooner you'll be able to see how your stitches look on "plain" fabric rather than over penciled or inked lines.
All of this is IMHO, of course.