The two leaves in the center were actually leaves I lost on the porch when I originally removed them from the plant. They fell behind a bench and got lost and forgotten but have grown at a faster rate than the two leaves on the outer edges which were sitting on top of a pot of soil. Once your cuttings have started to form roots you can pot them up and treat them like regular plants.
As you can see you don't need any special rooting hormones or chemicals or soils to root may of the succulents you have in your home or that you can find in your nearest garden center. You don't even need a whole plant if you happen to come across a leaf of a succulent plant you like or if you ask someone for a leaf you can propagate it and grow your own plant.
On my plant blog I get asked if Aloes can be rooted like this and though I've never tried it everthing I've read indicates that they are one of the few succulent plants that can't be propagated through leaf cuttings. Jade plants cuttings
can also be easily rooted.