Under Type set the FBm Turbulence and a level of detail about 2,6.
Switch to density
and also change the shading type to lambert
change the Light scattering to Rayleigh
Now its time to add some fire to the smoke
go to the create panel, helpers and choose from the drop down menu After Burn Demons and drop the explode icon on your viewport.
Set the following settings for the explode (click on it and watch your panel).