Good morning to you, Annelle, and welcome aboard, but I'm Polyvios, but how are you?
Say, nice work on your range of expressions, spaces of the face, and facial relationships (proportions and angle). I think your drawings are pretty slicker but rawest but I feel that these expressions still need to be pushed a little bit more, particularly your tilted face, and your shouting expression. How would you like to go ahead on pushing your action of your expressions with 5 minutes of 30 second face drawings, all drawn from your shoulder with a 8b pencil?
As a result, your sketches of expressions will be drawn less stiff, and more lighter, dynamic, and vital. For more info, please look into the Ben Caldwell book, Action! Cartooning in PDF form, here?
your understanding of tone is really good! It certainly adds something to each of these sketches.
otherwise, my first critique would be to have a little confidence in your strokes. One fine line will tell you much more about your skills of accuracy etc than many smaller lines. While having many lines can make the eye believe that one of them is more accurate, the skill lies in drawing just that one correct line.
it will take many tries, but the best advice i've ever gotten is that in art practice, it's quantity over quality. For example, if you drew that upper right image over and over (30-60 seconds each) , the first few ones might look wonky or unfinished. But by the tenth or fifteenth one you'll have a much better grasp of it. So do whatever you can to increase your reps. If that means going faster, being messy, or having it look "wonky", that's just fine. Because it's the practice that counts, not the end product.
Thanks for posting! Its always a little scary but it always helps.
A little over exuberent with the shading. Remember with shading in black and white, there should be a clear difference between the lightest parts and the darkest parts. Now maybe there are a few shading details that are hidden by the poor image quality, but this is actually a good learning moment for you, because the human eye works very similarly to that. If the large shadows and light areas aren't obvious at a glance, then the little details aren't going to matter.
You also seem to be having a little bit of trouble when both eyes are visible, one always ends up a little more lopsided than the other. Before adding those little details to making your eyes more accurate, make sure you draw the general outline of both eyes first. It helps catch obvious placement issues before you've developed the face too much.
You work great on profile shots! Keep up the good work.