I really love dark walls, but unfortunately, they have a tendency to make rooms feel smaller if not done right.
I've heard about this and it really makes sense.
If you are good in drawing, you can draw in your walls (I'm planning to do this), otherwise, you can simply find some wallpaper to put in the walls (but I think it's hard to find, in the chinese stores near me, the cow pattern makes success XD)
Other thing that, in my opinion makes a good decoration, are those things where we put the candles (I don't know the name of it --"), the big ones. One day I saw one that looked like a torch with a skeleton hand holding it. I was, like ->
I-WANT-ONE! XD because I love that stuff. Unfortunately, it was too expensive for my pocket =/
Dried flowers are also great. Sometimes, when me and my mom go on a walk, we just pick some flowers and dryed them. We own a lot of these: http://user.img.todaoferta.uol.com.br/J ... hoto_0.jpg
Here, we call them "fox tails", don't know the name that you give them, but they grow a lot, near us, and they are really fluffy
Another thing very good to use in decoration are skulls. When I went to Gandia (Spain) on March, with my friends, we went into a store that sells decoration stuff. One of my best friends called my name and when I reached him, he showed me a skull with a rose and a dagger, it was so beautiful and it wasn't expensive. But I don't buy it because I was afraid (and with reason) that it could break in my way home (the bus drivers kicked our bags inside the bus, literaly).
And last, I'm a big fan of posters (don't mock, here is almost impossible to find another things). My favourite one is a Nightmare Before Christmas poster, similar to this:http://magicalmoviereviews.files.wordpr ... 1/nbx5.jpg
But just the image and say "Tim Burton's The Nightmare Before Christmas". It's really big
Anyway, this is my opinion but I hope it helped (not in the paint-walls issue, but in the decoration XD)