Hi people...
I do not know if you all have noticed, but right now in deviantart, those that have a subscription and activate the beta testing have access to a brand new feature: the critique request.
When submitting a deviation, you can request for it to receive critics and a new option appears under your deviation for people to leave well constructed comments.

I find this is one feature DA has been lacking and I think it is one of the best improvements lately. I have activated it on my latest deviation (here on the left) and if it has yet to receive any critic, I believe this is a tool any artist out there could use to improve himself. It was hard to tell until now if an artist would welcome critics in his pieces, but now it would become clear. On top of that, you should not be scared to use it, since you need to approve the comments left in that field in order to have them appear to the public. If you find that some of those critics are nonsense you can simply leave them hidden.
Still, this option has a terrible drawback: you can't tell if a piece has the critics activated until opening it. I plead guilty here and confess that many times I do not open deviations when I do not find the thumbnail interesting. But now, the artist I am watching might be expecting some feedback on his work and I can't tell if I do not open it. It could have been better if DA made it so that critic open pieces got some kind of distinction, but that might come later since it is still in beta phase.
Anyways, I am more than eager to try out this feature, so, if you too want to try it, leave here a comment with a link to one of your deviations open to critic and I will do my best to give you honest feedback.
We all need to improve and this new tool might be the awaited tool.
EDIT: it appears that only beta testers can see this new 'critique' field in the deviation page. That's a shame. I hoped DA wanted us to really test it, and how to test such a feature only between beta testers?
Well, I hope this feature becomes available to all as soon as possible!
Link to the Critique faq:
FAQ #95: What is the Critique Feature and how do I use it?