I actually had to go look it up. I've never done one either. -Urban Dictionary- Art Trade- Commonly on DeviantArt, when two artists exchange drawings for each other, particularly when drawing each other's character. So, yeah... that's what it is.
In that case, just PM me a request, or leave one in my art thread. http://www.everypony.com/forums/showthread.php?12865-Ridley-s-Aesthetic-Atrocities/page3
You at least seem to understand basic color blending and composition. Compare your apple tree to this Jackson Pollack painting. This mess of paint drips is worth one hundred and forty million dollars.
you have to look deeper into the painting. Only then can you see that it is just paint splatters. I hit 20,000 GO ME!!!