How do you keep the tension when tying that? With a regular shoelace knot, I have a spare thumb to place on the base knot so that it maintains the tension I ini

How do you keep the tension when tying that? With a regular shoelace knot, I have a spare thumb to place on the base knot so that it maintains the tension I initially selected with the base knot. With the Ian knot, it feels like I just get whatever it feels like giving me.