Pick a pitch close to your speaking voice pitch.
Tilt the head back and SMILE
Resonate the respiratory tract by:
On the inhale, rattle the septum and 'creak' the traches on this pitch:
On the exhale, gargle a French 'R' on this same pitch:
On the diagram, notice how the trachea, where it splits in two, snuggles up against the upper vena cava that brings deoxygenated blood back to the heart, and the upper vena cava snuggles right up against the aorta.
Since blood, like water, transmits sounds well, any resonance of the trachea is passed through the bloodstream to the whole body. This is why ten good snore-purr-snarls will tingle and fingers and toes -- and dissolve all lateral tensions (armorings).
Note: tilting back the head can help both the inhale and the exhale sound come from the same area of the throat without changing the throat/mouth muscles' positions.
It may take a few tries to 'locate' both sounds in the same area. As mentioned earlier, smiling also helps position both sounds within the same relaxed throat area.
You might also view the Sky-Pointing Tracheal Flutter version of this gradually evolving exercise.