The edge of the nose skin needed to be trimmed back, and after a half hour I was getting increasingly frustrated with the wavy results. I had similar problems getting straight and smooth cuts on the rudder nose skin using snips at the Zenith factory, and the guys there assured me it wasn’t just bad technique - it’s an inevitable result of using snips.
I remembered a thread I had read online previously about a miracle cure, so I thought I’d give it a try. I ordered an Olfa plastic/laminate scoring blade from Amazon (1090486 PC-L) with PB-800 tungsten steel blades.
It arrived today and I gave it a try with great success. Just hold a straight edge against the skin, score (with fairly heavy pressure) 3-6 times, then bend it a few times and it will snap apart with extraordinarily clean and straight edges.
Compare those perfect edges above to these ugly cuts made using my old method with snips and a file: