You can do the tourniquet method.
This is my understanding of the method from reading Five Final Acts, and it's advised to practice so you notice the point at which you start to feel light-headed, and to work with the object hitting the collar bone/shoulder. In my experience, I don't have the cartoids for partial, or for tourniquet, so I don't get the pleasant light-headed feeling, I get the head pounding.
Put the ligature around the neck, and to the side, wrap it around an object like a wooden spoon or a cooking spatula, although something smaller can be used. Lying down or sitting up against something like the back of a sofa or a wall, twist the object quickly until you feel light-headed. When going all the way, don't pause, keep going twisting quickly. The object will naturally stop against the collar bone, so when you lose consciousness, it won't let go.