Everyone has his or her own favourite knots that are often used when fishing. I’m sure you have a couple of trusted knots, too.
I know some friends who use the slim beauty knot when they need to connect two leaders or tippet together.
The slim beauty knot is also used to connect a leader to a wire trace for toothy predators.
The attraction of this knot is its slim profile and knot strength.
From experience, I know you have to absolutely get the knot right or it will fail. When I first learned to tie the slim beauty knot, it felt kind of complicated and ended up anything but slim.
The below video by RIO absolutely nails it and shows very clearly how to tie the slim beauty easily.