Stone shapes was created from reference in maya. I found them in very good texture pack by Joost Vanhoutte
this is his gumroad page https://gumroad.com/joost. Hi's doing great work go support him!)
Every stone are sculpted in unique way from one side but in the end they look the same O_o )
I use only two brushes - Clay brush with square alpha for edges and Trim Smooth Border with Color Spray Strokes. For finish touch - Custom Dots alpha for kind of pores on stone surface.
For mortar - Clay Buildup with color spray and Standard Brush for different Height on surface between stones
When I finished with sculpting I made a mistake that totally forgot about tilling T_T so that's why you can see wooden trim. Basic technic with wood - create heaght map from photosourse that I found on textures.com and using Projection Master in Zbrush project them on basic blocky shape and sculpt on edges with Mallet Fast for wooden look.
Then just tile them with Offset in zbrush
Baking was made in XNormal
For texturing I used only photoshop and couple photos for start. Then a lot colored overlays and hand painting for achieving look that I want.
and rendering in Marmoset)
So ... thats how I made a Rough Stone wall texture
I khow I made a lot of mistake texting it so be with me - I try realy hard to be understood
Thanks for your time and feel free to ask me anything!