Awareness has helped me a lot. After I posted, I realized that I was not engaging my inner thigh muscles very much, whether standing parallel or in turnout. So I started practicing engaging them a bit more in front of the mirror, and by doing this managed to straighten out my knee/ankle foot alignment.
Now I "practice" this all the time, as well as noticing whether my hips and shoulders are straight as well. I periodically check this out during normal activities - especially when I'm walking - it works great when pushing a stroller because I have the nice straight line of the handle in front of me as a reference point.
Then I try to "translate" that alignment into very simple (and gentle) barre exercises (tendus, mostly, also I have a tendu - plie combination barre exercise that is a good test of alignment and weight placement), both with the "barre" (usually my kitchen counter) in front of me (this way I can line up my chest and hips, too) and then with it on one side.
Within a couple of days, I've noticed loads of improvement. I guess I was a little quick to get frustrated! Maybe some stuff like this would help you - you can sneak them into everyday stuff pretty easily (like when you're in the ladies' room, if no-one else is there)
For me, it seems like a big part of this is needing to retrain my muscles - get them used to holding things together in a slightly different way, regardless of whether or not I'm dancing.
You have a bit more of a challenge, since you have a more "structural" problem than I do, but maybe it would help - might be good to check with your doctor/chiropractor to see what they say...