To make a VFT leaf-cutting, you firmly grasp a leaf by the petiole, and with a downward tug (making sure to hold the mother plant down so it isn't pulled out of the pot!) pull the leaf off of the base, making sure to get some of the whitish rhizome on the bottom of it. Take the cutting, and set it in some sphagnum peat, with the white bottom covered with soil. After a few weeks (or months, years...) baby plantlets will appear from the base of the cutting.
The only problem I've had so far is when I pulled off a dead leaf, the base was a big part of the rhizome, and I took about 60% of the roots with it. The plants seem to be doing okay though.