Woah, these are awesome, I love them!

I simply love these. I love the blue eye especially since it has that vertical hatching effect more visible immediately. I would love to see this style used in your pieces :D!

Love the different eyes you did! It really shows how just the different shapes of eyes and the different colors effect the mood and gives such different feeling to them! I also really like the oppositional balance of the delicate details of the eyes and structured feeling you created with the pencil strokes on the colored skins! Really well done!

I love the use of pencil strokes as well instead of blending, I think it helps us to clearly see the choices you make as you complete the image. One thing that I think may be cool to try out is to handle the whole image in the same way. For example, looking at your eye studies, it looks like for most of it, you used vertical pencil strokes for the rendering. I think this is a cool stylistic choice, as opposed to using strokes that follow the form. I think your drawings can feel a bit more unified if you handled the whole drawing in that same way. Try to lock yourself into ONLY using vertical pencil strokes to render out the Pupils, eyelashes, eyebrows, etc. Currently, I think the way the rendering was handled for these areas kind of clashes a bit with that bold style where your pencil strokes are apparent. That's just my opinion about experimenting with style, so you can take it with a grain of salt haha. Hope this helps!

Going for the things that you like to create is the best way to stay in the process! You should definitely keep on going. I also like how you added the colours you used on the side, it is a simple, yet great addition. Keep it up!