[Do Not Erase!] challenge

So recently I have practiced this exercise in my sketch-book which is about how to control using the eraser while drawing/sketching. It is a fun yet challenging exercise for every artist. Practically, I have failed in that challenge because I have used the eraser in every sketch, however, I am surprised that I haven't used the eraser as much as I used to do in my previous drawings. (Sorry for the photo quality and size, they're all taken by a mobile camera)

Eraser used twice. Time taken: 15 minutes

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21092011148.jpg (85.57 KiB) Viewed 171 times

Eraser used six times. Time taken: 25 minutes

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21092011153.jpg (93.79 KiB) Viewed 171 times

Eraser used once. Time taken: 20 minutes

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21092011151.jpg (119.69 KiB) Viewed 171 times

★ I'd appreciate your reviews, comments and likes. Thanks in advance!
Reference used: LOOKBOOK - SEPTEMBER 2011 - WOMAN - OFFICIAL PULL & BEAR WEBSITE

Hello~!

Woah, I really liked the last one! Oh, by the way, on the picture of the first one - you wrote "2" under "15MIN", but you titled the picture saying the eraser was used 6 times. And on the second picture, where you've titled "Eraser used: 6 times", under "25MINS" on the picture, it's written "2". I think you accidently switched them both up. xP

Oh, and in the second picture, the lady showing her back, you'd ought to make her hair (the one which is resting on her back) slightly larger. Since she has pretty long and quite voluminous hair, it seems awkward since it fits in a small bundle around her neck. (I'm sorry, I can't seem to explain this well. Just look at her hair in front of her, then the hair on her back, curled around the neck, and you'll know you got to make it bigger.)

So, yeah. As I said before, I love the last picture and found it quite amazing how you used the eraser only once. She is all so ganster and all :'D

Erm- right. Well done! Keep it up!

-TMuffs.

Sorry about switching the titles, I am going to correct it now.

Hey Starlight9. It's been a long time. Okay, here's my review!
The first sketch is pretty good. You only used the eraser two times so that makes it super good. I would suggest you to try working on the shading. Some areas can be shown dark while some are grey where light is shining on them. And just a tip: Try practicing similar sketches to get the proportions right. The first one's good. However, I don't think I can say the same about the third picture. I'll come to that in the end. First the second sketch. The girl seems beautiful! It's the clothes thingy again. The folds are not that visible but I can see you put an effort into it. (And I wish I had hair as long as that!)
Finally the third sketch: The first thing that caught my eyes was the girl's arm. It looks broken! Is that what it's supposed to be? The legs seem a bit too thin... But overall the sketch is great since you used the eraser only once here. So I think the first one was the best because it was done quite accurately (to my belief because I haven't seen the real thing so you'd know better about that than me) and also because of the fact that you used the eraser only twice there. (That's what amazed me the most)
So you should definitely practice sketching without using eraser. Also try sketch while using eraser to give the lighter shades (just for fun, you know).
Anyway, I hope I haven't bored you here. Keep on drawing and I'm sure you'll get better in no time.