I find for figure 8, parallel works best for me. I think I go past parallel til I am looking at my target out of the corner of my left eye. I looked up baseball pitching tutorials, they helped with the stepping forward.
On the other hand, I use a 45 degree stance when using helicopter/byzantine.

Oh and I have to add, Brian Grubbs has his style down to a science! Here's a big shout out to him and the others on here who have made tutorials, thanks amigos!

I don't really use the figure-8 anymore. However, when I do I more or less do what Brian Grubbs does, at least in the first 2/3rds of the cast; feet together, and at a 90 degree angle from target, move front foot forward and maintain 90 degree angle, but during the final cast/follow-through, I pivot into something sort of like a modern Sabre fencer's footwork, with the front foot facing the target dead-on, and the rear foot somewhere between 45 and 90 degrees. (Heels may or may not be aligned.)

In my experience footwork is important, but if you're going to assume a stance where you face 90ish degrees to the side, you have to pay an equal amount of attention to how the upper body is oriented as well.
A lot of people think they're facing 90 degrees, but more often than not have this bad habit of facing the opponent with their upper body more than they realize; resulting in an awkward twist in the waist that can throw you off more often than not.)