Here are the posts I marked as _**Needs Improvement**_:

###[Photoshop shows outline around mask when exported to PDF][1]

The question would be improved if it had a screenshot displaying the problem. It doesn't help that the OP never responded to [Dominic][2]'s questions.

The answer suffers from severe formatting issues. There are 6 solutions, but they are all mashed together. Steps should be formatted with ordered lists. 

###[How do you choose the spacing between letters in a diagram?][3]

This has the potential to be a decent question, but my biggest issue is with the lack of information: _what_ is a diagram? That could be anything, and the answer certainly depends on what sort of diagram we're talking about here. On a large format poster? A small aside in a magazine? In a bar graph? Way too broad as it is worded.

###[Command line program for adding curves/levels to an image?][4]

Not much room for improvement in the answer, but I still am not a huge fan of link-only answers. Quote the linked section if you have to, _something_ is better than just a link.

###[How can I draw a water wave in Photoshop?][5]

Another link-only answer, and what appears to be misuse of [tag:software-recommendations] since Photoshop is specified in the title.


  [1]: http://graphicdesign.stackexchange.com/q/21891/8708
  [2]: http://graphicdesign.stackexchange.com/questions/21891/photoshop-shows-outline-around-mask-when-exported-to-pdf#comment30366_21891 "Does it appear at any zoom level, or only at some? Have you tried printing it to see if it appears in print? Sometimes there are unexplained artefacts in PDF previews that aren't there in print or at different zoom levels."
  [3]: http://graphicdesign.stackexchange.com/q/21640/8708
  [4]: http://graphicdesign.stackexchange.com/q/22058/8708
  [5]: http://graphicdesign.stackexchange.com/q/21855/8708