1. Be absolutely sure that your feed dogs are down.
2. Wear Machingers gloves.
3. Use a quilting foot (also called a hopping foot, with a spring in it. Never even think about using a walking foot--not the right thing at all for FMQ.
4. Make many, many practice sandwiches.
5. Be sure your quilt isn't creating drag by hanging down from your machine. The weight of it has to be supported on a table or some other support so it can move around as you sew.
6. Make sure your machine bed is as clean and slippery as you can make it--silicone spray, sometimes just something like Pledge (be sure to wipe off every last drop of this).
7. BE SURE to bring up your bobbin thread through all the layers of your practice sandwich or your quilt and hold the bobbin thread and upper thread (about 7 or 8 inches) in one hand, behind the needle. which will keep your tension right as you begin to sew. This is a VERY important step that I finally learned from an expert.
Good luck as you learn--loads of good tips here!