Originally Posted by Peter Möller
From what I understand the heels should be under the hips and the toes turned out to about shoulder width.
This is a starting point to finding the appropriate stance, not the appropriate stance itself. From this position, you need to experiment to find what works best for you. Keep it simple - open the hips to whatever degree feels comfortable and allows you to sit in completely and upright, then place the feet under the thighs and parallel with the thighs.