This was made out of filters, and overlaying, from the start of the image i cleaned up alot of the wall and its dodgy areas like weeds, eroded areas of the bricks etc.
This took me roughly 3-4 hours, it isn't the most advanced of pictures around but i believe the impact is something nice.
My Verdict:
Pro: + I like the grunge // graffiti style + Lighting works + the graffiti looks somewhat realistic
Con: - The spray can is a tad too large - The paint from the spray can wouldn't create a pool as thick as the image shows, but hell spray cans could who knows - I cleaned too many weeds up and cracks in the image which lost its dirty graffiti feel.