I was always taught a firm solid base, feet at least shoulder width apart......
I was also taught a very useful drill of feet together to aid timing, syncing body and arms together....
it was at the range last week I did the drill and found my iron shots only a few yards shorter so I've narrowed my stance and it certainly promotes a better hip turn which is the main thing I dont do properly. I tend to get stuck and sway forward in the downswing as opposed to turning. working well so far