French Knot (Double Wrap)
Bring the thread out at the required position, hold the thread down where it emerges with the left thumb and encircle the thread twice with the needle. Still holding the thread firmly with your thumb, twist the needle back to the starting point and insert it close to where the thread first emerged (not in the exact place or it will simply pull back through). Pull the needle through to the back, leaving a small knot on the surface, as shown.