I have a habit of associating increased airflow through my mouth or nose with the sensation of air passing through these organs. There are two ways to increase this sensation:

1. Expand and contract the diaphragm muscle more energetically.

2. Constrict the throat or nasal cavity.

You will note that method 2 does not achieve increased airflow. Not an original observation, just something I need to work on.

Wind instrument players are instructed to keep an open throat. The reason often given is that the throat resonates with the instrument, improving the tone. I doubt this, I suspect instead a constricted throat is less expressive: changes in diaphragm tension result in less change in airflow, resulting an a less expressive performance. An open throat allows articulation with the diaphragm in addition to tonguing.

This is somewhat like opposing muscles locking a limb in position. It works, the limb is immobilized, but it's also less reactive, and it's burning energy to keep the muscles engaged. A martial artist will therefore try to maintain a relaxed, reactive state. However control of this state requires more practice and attention.