I agree with bobpuls. I use something like this:
https://www.amazon.com/gp/product/B000P0LNRE/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
This would work well too:
https://www.amazon.com/gp/product/B000P0LNRE/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
The important thing is that the scissors are sharp. And, again, I think you are overthinking the whole thing.
If the cut isn't perfect, it really does not matter much. And once you put edge tape on--if you do--nobody can see the cut.
The tricky part is starting. I saw a few videos where the person started cutting with the handles of the scissors above and below the handle like this:
View attachment 21609
I just don't see how that would work well unless you had a scissors with handles much smaller than the ones I am using.
I was taught to do come from under the handle like this:
View attachment 21610
To start the cut. And once you are a few cuts in, then everything else is easy. I know some guys who leave a little wing near the handle because that makes it easier to cut. But it also gets the rubber to give you more feeling. The excess flap near the handle gives more vibration. I think it actually looks cool.
Here is a video of cutting with the scissor handles around the handle of the blade:
Here is a video with someone doing something like what I do. But he does it upside down:
In truth, in one way, this may be better than what I do. I like seeing the blade and the edge of the blade. So I am coming from under the rubber. The big risk is, until you get the feel of it, you can pull the rubber away from the blade at the corner where you start. After a few times you learn how not to do that. The way shown in the video, it would pull the rubber towards the blade. But once you are past the handle, it seems to me you are cutting blind.
But the guy in the video seems to cut fine that way.
Just don't worry about it. You are not going to ruin the rubbers. If that edge comes away from the blade, glue on a business card and slide that between the blade and rubber where the rubber has started to separate and then re-press the rubber to the blade.