My way of practising this is to go to the Facebook pages of local pubs where they put up loads of photos from the previous night, and try to draw the faces.
I’m improving slowly.
I can’t post the reference photos obviously but take my word for it these are all the SPITTING IMAGE!
I’m doing the shading with a pencil at the moment. I’m sure there are better ways. I’ll be looking into it when I think I am ready to try doing these live.