I think I get the footwork aspect (though I could be wrong)...the x-step is very similar to a crow-hop I'd use when playing outfield in baseball, with the obvious differences in that you are looking away from the target and that you are looking to get your last step crossed over the target line to help get the hips turned (kinda a weird hybrid of a golf swing and a baseball throw).
Where I'm really struggling is figuring out how to transition the power I'm building with the x-step, lower body rotation, etc. into leverage on the disc. I feel like I'm getting myself into a really good position with a lot of stored momentum, big shoulder/hip turn, good reach-back, etc. and then just poof it just disappears as the disc slips weakly from my hand. Not 100% sure my grip is correct (bit hard to tell when the only thing I have to compare it to is pictures online), so that may have something to do with it. But really I feel like I need to "pull" on something to get that speed built but I can't really feel intuitively where that resistance is supposed to come from.
Oh well I'll keep trying and hope it will come eventually! I found a deal on new Z Buzzzes and bought 5 of them (couldn't help myself!) so at least now I'll have something consistent to throw to see what's me and what's the disc a bit easier.