Tips for propagating Echeveria (Fleur Blanc)
A lot of people will tell you to slightly bury the bottom of the leaf. You can also dig a little on the soil and dip the plant into the dirt, and pop the leaf into it but do not cover it with dirt.
Some people achieve better results by simply covering the bottom of the leaf with a small pebble. Some others have problems whenever they cover the succulent with dirt: they experience mold and eventually rotten leaves.
When it comes to watering, set your spray bottle to stream instead of mist, then squirt little puddles down around the leaf and new roots when they start forming.
This is a better way of doing it in my experience since you don’t have to worry about the soil/grit staying damp for too long.