Page 28 - Patrick Moreau, Jean-Benoit Heron Marine Knots How to Tie 40 Essential Knots

1 and 2 - It is essential that the two half hitches are always knotted in the same direction.
If, as in the diagrams, you tie the first one by first passing the working end under the fixed
standing end, you must tie the second one by first passing under.
Of course, there is no reason that you cannot start with the working end passing over, as long as
you knot the second one over, too.