how do to grafit art on photoshop

Hi

now i am gonna tell you how i did my Awsome poster

first i found a picture of concret i am using as a backround picture
Find you picutre that you like and want to use
Edit so you get away all the unwanted items
Use a tool that will make the edges clear, giving it a grafiti "look"
put it in as a layer on top of concreat
Change the opactiy to make it fade in
DONE!