The drawings below aren't anything groundbreaking, and I only did it a few times as you can see, but it really gave me a good lesson. And another thing happened. I wasn't even trying to get a likeness. Say what you want about the drawings below, but I'm pretty sure you can tell who two of them are. The other guy was a guest star I didn't know.
But what happened was pretty cool. I shut off the trying to draw something specific switch and switched on my OBSERVATION SWITCH. I was going for the expression (not just the mouth). Drawing what I saw. I didn't judge it. On Baldwin though, I did say at one point "that's not quite right, why doesn't it look more like him (here or there)" but then I LOOKED at what was different. Like looking at a model sheet when animating. The space between shapes & lines. "The back of the head is this far from the ear" etc... and when I refocused to see how it worked ... it worked!
Anyhow, you be the judge. The 1st drawing of the gal obviously isn't as on the money as the 2nd. And she was wearing glasses, but oh well. It was a lot of fun and I'll be doing more of it.
This drawing was one I had really ruff on the 1st page of my sketchbook for a while, I put detail on it and cleaned it up a bit that night to warm up. That's something else I find good to do. Sketch something really quick without intending to finish it. Then later on, go back to it to warm up or to look at it with new eyes.