Take it with a grain of salt, but my understanding is duck feet (outward turned feet) is a lack of internal rotation in the hips and the hips being pulled into external rotation. I have this slightly in both feet and have been using this technique to improve it (with good results after a couple weeks) and a few of the ones outlined in Becoming a Supple Leopard.
Again I am no expert by any stretch, but working on my hip internal rotation helped me.
I see this all the time in our PT clinic, and 99% of the time it's the right foot. I have an unproven theory about that: Maybe driving with your right foot externally rotated all the time has something to do with it. Next time you have your foot on the gas pedal, check out your foot position. Maybe driving with straight feet will help. (It worked for me.) Smashing the glute medius and squatting with neutral feet should also help, as will developing stance awareness, as Kaitlin suggested.
I think I cleaned up my internal rotation, but I still have a wod of tissue high hip/tfl area that won't go away. My test is the wall squat with back on the floor. I need to do goalie stretch with band And then hip internal rotation to clean it up.
I think everybody should find out where their femor needs to go. I think mine should go to the side of the socket and then back. I dunno -- just thinking out loud.
I have to agree with KEN ROSE on this one--I have found this to be the case not only with myself but with countless others I have observed. Driving is the worst! Take care to place the heel correctly and it will help out a bit, but of course further work outlined by others will be needed as well.
