I don't think I have the exact answer, and I don't think that there is an exact answer as grunge like other kind of digital imagery is extremely creative and depends on the artist vision.
Normally these images or creations take a lot of editing, many hours in Photoshop, a lot of frustration and unsuccessful work that end up in the garbage bin, that's part of my experience and like many of other digital art, patience and practice is required.
The grunge effect can be described as dirty, gloomy, dark, old, eerie, using textures and mute color.
The urban graffiti-like design is often done using one, two, three or more images.
The following images were done using textures, vectors, one to 5 images and hours of Photoshop editing.
|City Woman with Tatiana Vladimirovna, done with 2 images, a lot of texture and editing|
|Miror, only one image using texture, brushes, and vectors.|
|Help me with Jessy Cortes, using 2 images, textures, vectors, brushes.|
|Dream with Christina Patterson, using 5 images, textures, brushes.|
|Bullet Man, using 3 images, texture and brushes.|
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