1) Open up whatever picture you want to do this on. I used Veronica (Camila Mendes) from Riverdale because I'm in love with that show.

2) Open up the cut you're going to use, I just googled cuts on face and found the one I was looking for.

3) Use the Pen tool and trace out the cut, then right click and press make selection. After that, click on the layer and press resterize layer. You can then move the cut freely. Then erase the face because you don't need it anymore.

4) Place the cut where you want it, I put the layer in pin light mode to make it blend in better. You can use the eraser tool in a small size with the hardness on zero to refine the edges and remove and skin leftover around the cut so that it's more realistic.

That's pretty much it, I tried to make it as straight forward and simple as I could for you guys.

Images I used: