These are great! Love that Harry.
I don't really have much to add because Forelourne pretty much covered what i was going to say.
A lot of time when you're drawing from a photo/screenshot/still/etc. the lighting and shadows are all right there for you, so definitely pay attention to that. Sometimes it's even a good idea to figure out from what direction the light sources are for future work you do where you aren't using a reference.
The beauty of having internet resources is that a lot of time when you need help figuring out how to do shadowing, you can google it(for example, googling "light from below [face]"), and get some pretty decent examples. Also, and you'll see this a lot from me, never be afraid to use references or tutorials, it's how we learn. Almost everyone uses references.