found this on google
Leaf Cutting
In this type of cutting for cloning plants, the leaf blade itself is used to create a new plant. Usually, the cut leaf doesn't become a part of the new plant.
If the plant you are growing has particularly thick leaves, you can cut open the veins of the leaf and plant it flat into the growing medium, making sure to keep the cut leaf exposed to light and moisture. After a short period of time, new plants may begin to form where the leaf was cut open. The cut leaf will eventually dry up and rot away, even as the young plants thrive.
Another technique sometimes used is to take older, larger leaves and cut them into triangles, making sure each piece contains a large vein. The edges of the leaf, which usually contains no veins, should be thrown away. The triangles are then planted in the medium with the pointy side down. A new plant can then develop from the vein.
Be aware, however, that leaf cutting is very delicate, and only works with plants that are easily cloned.