Other contributors have said "How do you feel your iliopsoas muscle?" is the same question as "How do you find your iliopsoas muscle?" If you believe that these are not asking the same thing and should be answered differently, click here
Lay down on the floor face up and gently press your fingers into your belly between your hip bone and your navel. You will feel it tighten up as you raise your extended leg slightly off the floor.
Smooth muscle is found in hollow visceral organs, like the stomach, intestines, uterus, bladder, and blood vessels/arteries. (Smooth muscle doesn't apply to the heart though, that's cardiac muscle)