They have been made ahead of time and put on a board to stiffen. How I just need to glue them on with slip. Notice I do not need to score the surfaces, I just use pressure. This works because the handles are applied to the mugs at the same stiffness and I am careful to dry the pieces evenly.
In ceramics, handles need to be applied to many types of ware. There are things to know not just to make them look good, but to be strong, durable, practical.