Hey Jeff - I'm a fan of lexan shears for rough cutting (but it helps to have a couple different types/shapes of scissor because you will absolutely get blisters or hand cramps), then I smooth out my cuts with a belt sander and one of these big flappy wheels on a Dremel/rotary tool, and finish with emory boards for a smooth, pinch/bite-free, slightly-rounded edge. Links for inspiration, but shop around.
Luckily on Anovos kits, the cut lines on the inside edge of the armor are easy and like 90% accurate if you're a standard sized trooper, so I usually mark them with a pencil, rough cut, then sneak up on my line with sanding. I only use a utility knife (AND A CUT GLOVE) and a metal ruler (with some magnets) to cut my coverstrips in straight lines really, which isn't needed for this kit (unless you make inner cover strips, which you should!). I know some people score-n-snap, but I haven't found many places on the armor that it's super practical/safe for me to do. Oh and wear a respirator. Hope that helps!