Wide and bowed
I remember how it seemed Seve Ballesteros looked odd when he was setting up to hitting those bunker shots and how odd it felt when Hank Haney and I were hitting bunker shots with a 5-iron. But when I looked at it, it made a lot of sense. You want to establish a supported base in a greenside bunker shot. What I saw with Seve and how Hank explained it to me was you want your feet wide, wider than shoulder-width apart. That is measured from the inside of your heels and that means it would be wider than your driver stance. To acquire the extra support, you want to bow your knees out to help this turn your feet out. When Hank showed this to me I must confess at first this felt weird - like any change in the golf swing - but I couldn't argue with the remarkable results.