All my scissors are sharper than a razor. In the 90s, an old seamstress learned how to sharpen them. I share the method in the comment

You won’t spend more than a few seconds on all of this.

However, if the scissors are very dull and don’t even cut the paper normally, a more serious sanding option is needed. To do this, you need to use fine-grit sandpaper.

Place it on a flat surface, such as the glass of a picture frame, and use the cutting edge to pull it away from you repeatedly. In the case of scissors, the metal has an angle here, using which the cut is made. You should align the plane of the cutting edge closely with the plane of the sandpaper.

All of these methods are suitable for utility knives and tailor’s knives.

Scissors designed to cut paper usually have a rivet, when it is relaxed they stop cutting. To do this, flatten it a bit with a hammer.