How to make a patchy cloud layer? I want to make a cloud layer like shown in this image (where parts of it are empty patches).



I tried doing this by applying a volume scatter shader to a cube and then controlling the density with a have texture but it outputted as such :


I need this to look realistic, how do I achieve it?
I tried applying the method of a tutorial by BlenderGuru, but could not get it to look patchy.

This is my setup:
You have to put a color ramp in front of the multiply node to crush the noise node input into something workable with a color mix.