There is already great feedback, so just coming by to say that your drawings look great, and keep at it!! :) @Natali Santini

I really like the tips from other people on this thread. Here’s how I approach the reference. I triangulated the eyes nose and mouth and make sure they face the same direction as the ref, then I use the Loomis head to determine the rest of the head. I try to be more gesture than the reference. Then I can shade in the shadow to visualize the form better. Comparing the ref and the drawing side by side at the end and use liquify tool really helps too. As other said, these hard angles are following a perspective grid and you can try to guess the perspective before blocking out the study. I hope I add new helpful information in this topic :)

These are really cool - the one thing that stuck out to me was that the chins on both of them look like they're too far forward, or perhaps your line under the chin makes them look slightly at the wrong angle. They're nice clean sketches though - I like your lines

The problem with Reilly method is that they're great for frontal view, but it's bad for 3/4 or side view, as it has tendency to make faces either too masculine or too older. Loomis is much better for this purpose, because it's universal. So I will advise you to focus more on the Loomis technique, especially the rule of third lines (dividing the face into three one-thirds) . I see that you're still struggling with perspective. Try to be bold with your perspective lines before putting any features in. It will save you time and effort, because if you start drawing with thin perspective lines, as you progress in drawing, the perspective lines will get lost and you will need to guess where the lines were supposed to be. Cheekbones are the hardest part in human face, that's without a doubt, because their shapes vary between people (high cheekbones, wide cheekbones, etc), and they sit right between the frontal and side plane of the head, which makes it tricky to draw. But if you keep it simple and clear, it will be a lot easier to draw. The thing to remember about cheekbones is they support the fleshy cheeks attached to the bottom part of the cheekbones. While cheekbones are sharp, cheeks are soft and round. Cheekbones naturally only have two visible planes: frontal and side plane, while the cheeks have three: frontal, middle, and side plane (see image 5). Cheeks behave like a pillow which fill the frontal concave part of the cheekbones (see image 3 and 4). When it comes to shading, I will encourage you to learn it as soon as possible. Because shading is integral part of structure and perspective. It gives us a better sense of 3D, because our eyes are accustomed to seeing value difference (shading) of an object to determine its shape. While lines can perceive shapes, but they're not as effective. But keep the shading simple: cast shadow, shadow, mid tones, light, and highlights. Try to avoid mixing them so they look smooth, or make the value difference too little. Keep them separate, and keep them bold.

Hey Natali, I'm impressed how structural these drawings are, nice job making them feel 3D. When dealing with planes, remember that to be 3D, a shape has to have a front, side and bottom/top. Don't get confused with all the plane changes in the face, there can be a lot. Start with the simple planes first, then break the features down into planes. You did a nice job of showing the planes of the nose. I did a quick drawing that I hope helps :)

I like your drawings. Regarding planes I've found very usefull to draw the asaro head over and over. I think there's an app with a model you can pose. Then, try to find those planes in your references. About cheeckbones, I think you could study the skull and make a ton of skull drawings from reference. I think that getting to know the bone structure helps you to see that through your references. Finally, about shading, I believe that's the same recipe that what I said above (and that's only my opinion). Study the skull and make hundreds of drawings to learn the structure. Study the asaro head and make hundreds of drawings to learn planes. Study basic shading and make a hundreds of excercises (Dorian Iten has an awesome video about shading here: https://www.youtube.com/watch?v=6vapw6n6FyU). I think that after practicing a lot of concepts separately, you get to understand them and apply them automatically in your final drawings.