Okay so I figure I would start some brain storming for you guys.  First thing is to figure out a theme for your skin.  Now your first choice might not be the one you end up with.    Stay away from over used themes *cough* WOTLK *cough*.  Also stay away from too specific of a theme like one class or one playable race.  Be creative... it counts.

Some generic ideas:

• In-Game Holidays (Hallow's End, Feast of Winter Veil, Love is in the Air  etc.)
• Tradeskills (Baking, Fishing, Smithing, etc.)
• Factions (Smokywood Pastures, Steamwheedle Cartel, Explorers' League, etc.)
• Instances or Raids

BE CREATIVE. . . . .

Some places to get inspiration:

• http://us.blizzard.com/en-us/community/fanart/
• http://www.worldofwarcraft.com/downloads/wallpapers.html

Remember you can't use things (ie images) from an existing skin.  This includes user made not just WowStead Official ones.

 It must also be Warcraft related... This does still keep it very wide open. 

BE CREATIVE. . . . .

Remember this is peer judged.  So it is you have to catch their eyes and like.

and don't forget...

BE CREATIVE. . . . .