I'm a lefty so this may be incorrect but I think you also want to keep good tension on the paper while you do it. If that's not a thing, then oops. Sometimes the glide works, the other 80% it bunches up about halfway through so I tend to try a few times then just give up. Also I assume it works opened more because the scissors tend to be sharper closer to the handle where they're less used, in case that helps anyone figure out the sweet spot. So just do what usual leftys do, make the contact between scissor blades pull together with a good grip, have a nice tension on the paper and push it through slowly. Then get annoyed when it rips after it working once.