For my background I decided to texture it in brick because most ally ways in NYC are brick. For my hand I made it skin tone and textured it with a yellow leather picture to get it having a similar texture of skin. For my knife I made it grey and used the blin effect to make it have a little shine line a knife would. 
Sources:
https://www.freepik.com/free-photos-vectors/skin-texture
http://www.trinitybrick.com/bricks