Alright, so I figured I'd start this one because I just started trying this today.
Basically, I find that if you crank your ankle as much as you can when you clipper, and then do a lot of the set with your support leg so that it extends nearly straight, that the bag will set alot straighter and true-er for the dex. I also find that for the dex, if you crank your body before the set, and then when you twist your dexing leg then you will end up nearly straight so you can hit the butterfly at the end.
Now, my problem is, that my shoes rub the back of my thigh/knee area, and it gets pretty red. I read this on the Nuclear Set topic as well, but no one really explained how to avoid it.
So, any tips on the scraping of the back of my leg, and then just tips in General for future people would be nice