Hi Becky, Well done on getting to 90! I've just started, just did #15 so I can imagine being a little tired of heads by the end. I suggest with the last 10, first have a look back through them and figure out what the main issue is that you've consistent struggled with, then work on that specific issue for the last 10. The two examples you've posted here are probably good to practice the Loomis method with as they are at tricky angles.

It's nice that you have come this far in the journey! I am sure you have progressed a lot. Do you draw from your shoulder or your hands? Drawing from the shoulder will make the movement easier. I feel like you were struggling with the drawing. If you already draw from your shoulder, so next. To solve the angle issue, I suggest you draw many lines and decide which one is more correct before moving on to add more details. And even more effective than lines is constructing a box. Draw a box (or many boxes) that reflects the perspective of the face, then proceed to draw the construction for Loomis method. You can either draw the face inside the box or draw the box in a separate page and use it as a reference. The annoyed girl face doesn't have much structure/3D in it compared to the other drawing. Think of boxes, of planes, especially for the nose. Your eyes' sense of proportions will increase with time, but for now, after checking the angles, use the pen and double check the proportions. At first, draw lightly and see if it matched or not, when you reach something nearer to the reference, go heavier with the pencil. And don't forget about deliberate practice. A 100 head is really a challenge, but why not drawing each face 3 times. Each time you will correct the mistakes you analysed from the previous trial. (And maybe count that as 3 faces, so still included within 100?) I haven't checked the challenge yet, so don't know if that's allowed or not. Good luck :)