If the thread spool is wood or Styrofoam, the thread is old and weak and should be replaced.
Always use a new needle for each sewing project. A dull needle or one that has a burr can snag the fabric or cause the thread to break. Bent needles can break or cause skipped stitches.
When threading the needle, wet the eye of the needle, not the end of the thread, to make threading easier.
Hand-quilting thread is not suitable for the machine.
Do not wind thread over existing bobbin thread, it affects the tension.