I'm currently working on the HSK6 study list. However, I feel that my speaking, sentence structure and ability to communicate have stalled. I've have contact with native speakers almost everyday and understand almost everything they say. I'm having a problem it taking my chinese to the next level: using more advanced vocabulary, so I don't sound like a 5th grader.

What are some things you guys do when you hit a wall? How do you keep making progress?

I think there are two approaches with any wall. Either keep going and work through it, or take a break for awhile and come back with fresh enthusiasm. Also know that you are still making progress, it's just slower and harder to measure the higher the level.

You are probably right. What are some resources you guys been using other than skritter?

Read some books? That way you'll get more regular exposure to advanced vocabulary than you would in casual conversation.

Many academic sources - for example, 'Achieving Success in Second Language Acquisition' by Leaver/Ehrman/Shekhtman - claim that reading is the most efficient way to improve one's general ability with a language.

I've been trying to read some articles, but I've trouble recognizing some characters which slows down my reading. I feel very comfortable with some texts around the HSK 5 level. Over the break I will try focus more on reading, see if it helps. Some of my friends bought me some books in Chinese.

Reading with software providing quick pop-up glosses can help with that. If you aren't already doing it, or if anyone else reading this has the same problem, here are a few tools, some of them made by Skritter users/friends:

Pleco's document reader for iOS/Android: http://www.skritter.com/forum/topic?id=163194441

Zhongwen for Chrome: https://chrome.google.com/webstore/detail/zhongwen-a-chinese-englis/kkmlkkjojmombglmlpbpapmhcaljjkde?hl=en

Perapera for Firefox: https://addons.mozilla.org/en-us/firefox/addon/perapera-kun-chinese-popup-tra/

Byzanti's Chinese Reader for Mac: http://www.byzanti.co.uk/

MDBG / Loqu8's Chinese Reader for Windows: http://mdbg.loqu8.com/

Read the few links from this post:
http://www.chinese-forums.com/index.php?/topic/34107-what-level-of-chinese-can-you-achieve-outside-of-china/page__st__60__p__255527#entry255527