Blackout...

While searching Google for tips on how to draw trees, found the blog of this America chap who an Artist/Poet - so he seems to suggests. Its quite a cool idea that might also be appreciate by you the reader. Or not, either way. There are loads more too...

And in case you want to draw trees...

http://www.austinkleon.com/2009/07/23/how-to-draw-trees/