There's no normals nor displacements, just a good seamless texture, UVs and vertex tweaking ✨
First create a fine texture, chose the scale of your details, and iterate on UV layout 🏁
(It's ok for me to spend time painting, but "art is always stealing" or watev🧑🎨)
Then break the heck out of your model 🤯 #Blender3d gives you nice tools to completly destroy your nice & beloved topology 🤖
🧰Destroy phase n°1:
BREAK all the proportions!
🪓Destroy phase n°2:
BEVEL all the vertices!
At least the ones sticking out. Don't just bevel, fiddle with the position of resulting vertices, to change the bevel slope & size.
🔪 Destroy phase n°3:
KNIFE all the stairs!
This is tricky, but results are GREAT 🌟. Basically, you create grooves on your geometry where there's something like it on the texture. Your topology is becoming very ugly, but who cares? There's no turning back anyway.
🎁 Bonus phase:
MORE KNIFE!
Concentrate on the resulting silhouette of your model. Modifications inside you model won't be as visible, if not completly imperceptible. Your texture does the job, it cries way louder than tiny modifications of your mesh.
Destroy phase n°4:
Extrude all the faces!...
No, not all the faces. I think 1 or 2 on each face. You can also rotate the extruded face.
I think that's it. Keep in mind that texture does a great job, and breakings only have to add details on the silhouette and overall shading.
Again, this is my (very new) way of doing things. If someone has comments, I would be delightled to hear from them!