I recently signed up to CGHub, a community of professional and amateur digital artists, both 2D and 3D. Not only is it a useful place to showcase work, what seems particularly useful is how active the forums are. Artists often have "sketchbook" threads where they upload their sketches, ideas, WIPs and finished pieces, and others are able to look and offer their opinions and constructive criticism. It's a great, laid-back way to get valuable feedback on your work and discover ways to improve. It's also easy to get into contact with other artists, offer your own feedback and advice, and develop a network.
Another useful area of the site is the 'challenges' section, where bi-weekly competitions are held in a variety of categories, including character design and creature design. The bi-weekly 'drawing jam' covers a huge range of themes, ranging from the typical such as designs for space stations and super villians, to slightly more unusual opportunities to test your skills and design something different, such as cherubs and redesigning Disney characters . I'd definitely like to become more active within this community so I can get feedback from more professional artists, and take part in the challenges and develop my skills.
A while back when we determined our 'areas of improvement', I wrote about how I lack a lot of confidence in my work, especially when it comes to sharing it online, and I often fail to actually finish my art to a polished, fully rendered standard. I also wrote how I lack an understanding of the industry and the sort of skills and knowledge I need to become more professional. I think CGHub is a valuable place to develop upon all of these weaknesses. I can share work, gain experience in talking with other artists, become more comfortable with sharing my work and understanding my weaknesses, and hopefully improve.