I did not look through all of those so I dont know if this one was mentioned. I use this one all the time and I love it.
I find and size my image. then I outline it with either a sharpie or edible marker, the goal being that you want to be able to see the flipped image when you turn the paper over.
Once I can see the image on the other side then I pipe the outline right on the paper, then lay the paper on the cake. Run the fondant smoother over the image and then use your fingers to run over the outline.
Gently lift up the paper and your image is then outlined on the cake.
Then you just pipe and decorate.