how to cut a tiger eye rough

It's "easy". All you have to do is orient it in all three axes so the flash rolls the way you want it to for your cab shape and the way it will be set.

I joke about it being "easy" because I've fought with getting it right. If your rough is one continuous 1.5" thick band it will be easier. If it's multiple bands you'll probably wind up with parts of the cab that face up differently from each other.

Wet the rough and look at how it's oriented when viewing it with the sun (or a really bright light) directly behind you and shining over your shoulder. This is best for use as a pendant stone. Holding the rough in front of you, rotating it "around the clock", and then rolling it up, down, and side-to-side will help you find the angle you'll need for slabbing.

Just imagine the rough face is hanging in a pendant. Find where the flash rolls evenly side-to-side, not going higher on one side or the other. Then, still holding it at that angle, roll the face of the rough up and down to simulate different sun angles.

For a ring stone you might want the light source more directly above your head, and you'd hold the visible face of the rough more parallel with the ground.

Hope this helps. It really is fun when you hit it right. I usually cheat on the first slab - making it a bit thicker in case I need to adjust the angle by regrinding the back.