Is your drawing digital or on paper? I like what you've done. The values are exaggerated, but they make sense.

Hey there! You are doing well for firt try. But I can tell what is your problem is. İt's a form and perspective issue. Loomis head is basically a combination of a box and a sphere. I'm talking about a box, really. And this important because in your drawing, you don't really give the sense of a 3D shape, it looks like a bunch of line floating in the air. You have to develop your sense of 3D space, shapes and perspective drawing skills. I have couple of exercise that you can do in a daily basis.  First of all, draw a sphere, and think about that sphere has lines around of it. Draw these lines. Do this over and over again until you became comfortable about it. And with that, draw boxes from any angle. Proko has a video about it. Check it out. This will help you to draw in perspective. Secondly, draw the Loomis head but instead of using spheres, use boxes. I dropped an example for that in the below. This will help you to understand the 3D'ness of the head. Last but not least, draw the Loomis head. Practice makes perfect at all. And by the way, you must do this exercises over and over again. This is not something to be done on the first try. Lastly, I'll put some 3D models can help you. Don't rely on them please, they are only tools but you are the one that has skills. https://sketchfab.com/3d-models/loomis-head-d0b3f4aa633a44d8bda8cfe2f779f1f8 https://sketchfab.com/3d-models/andrew-loomis-head-d2020b07408b4f238004f04d082a3193 (English is not my native language, so if there is something you don't understand, tell me.) Good work:)