Step your feet apart wide: a rough measure is to stretch your arms out in a ‘T’ position and check to see that your feet are just below your wrists. Some poses such as Parsvottanasana may take a slightly narrower stance – about 3 ½ to 4 feet.

How Wide?

You should adjust your stance according to the feel of the particular pose, given your own abilities.

-        The wider the stance, the more you will feel a stretch in your legs and hips. At the same time, stability in the pose decreases with a wider stance, and a too-wide stance can put undue pressure on your knees and ankles.

-        The narrower the stance, the more stable and secure the pose will feel. But you will feel less of a stretch, and a too-narrow stance may feel 'stuck' in the hips.

The Rule

The best rule for setting your stance is to adjust the distance to find the best balance between 

-        stability; where 'stability' means a sense of firmness and support, so that no muscles or joints feel vulnerable or overstretched, and 

-        opening; where 'opening' includes a good stretch plus a sense of mobility or greatest range of motion in the joints.

The one firm rule is that in all bent-leg poses such as the Warrior Pose, the shin of the bent leg should always be vertical, with the knee directly above the heel. This ensures that the knee will be strengthened rather than strained by the pose.

Placing the Feet

To take the Basic Stance to the right, step your feet apart wide, with the outer edges of your feet parallel to one another. Then

1. Turn your left foot in 45-60 degrees  (-- 'in' means toward the midline of the body--)

-        turn on your heel; this keeps your left leg straight and strong and takes the inner thigh back. This inward turn of your back leg sets your thighbone deeply in the hip socket and keeps your sacrum open rather than pinched.

-        Your kneecap should be facing in the same direction as your toes.

2. Turn your right leg out 90 degrees  (-- 'out' means away from the midline of the body--)

-        turn the whole leg, right up to the hip, so you don't feel any twisting in your knee. Again, your kneecap should be pointing toward the middle of your foot, in line with the toes.

-        Your two feet should be lined up with one another so that, if you were to draw a line back from the heel of your right foot, it would intersect the heel or instep of your left foot. Imagine you are standing on a tightrope, and line your feet up accordingly.

-        By keeping your left thigh firm, taking the upper inner thigh back and your outer heel grounded, keep your hips facing forward, rather than allowing them to turn toward the right foot.