Good Omens is one of my favorite series and I wanted to draw Aziraphale, one of my favorite characters, dedicating a portrait to him. It was interesting because I wanted to explore the visual effects of Photoshop after finishing the digital drawing.
The first version is the native digital drawing.
Version 2 instead would be "Film Grain" is my favorite, it adds that cinematic touch that I think can be good for a portrait of this type.
"Spatula Effect" instead is more subdued but adds texture that still gives a more retro effect.
"Sponge Effect" gives a more ancient tale appearance, I particularly like it because it tends to remind of an ancient book of fairy tales.
All these effects add noise to the original drawing, personally I prefer when there is noise because it makes it more "alive".