In my current Yellow Castle inspired build I am currently working on sections of the castle which are made of sandstone and I am employing two distinct textures to hopefully suggest this material to the observer.
To come up with these textures I have looked at various reference images of stone walls and stone paving that I found on the internet and tried to mimic the way light and shadow falls on the stone through the use of the dimples in the masonry profile bricks and the rounded plates, tiles, and ingots.
Wall texture
For the walls I am using a texture very similar to the one I used for the walls of my previous castle build, The Fortress of Falkenholt.
It is made up of 1×2 masonry profile bricks, 1×4 masonry profile bricks, 1×2 bricks, 1×1 bricks, 1×2 plates, 1×1 plates, 1×2 rounded plates and 1×1 round plates.
I try to place the elements as randomly as possible, to get a mix of large and small parts near each other and an even spread of texture across the wall.
Paving texture
The second texture is primarily used for paving, and is made up of 2×2 tiles, 2×2 corner tiles, 2×2 round tiles, 1×2 tiles, 1×2 ingots, 1×1 tiles, 1×1 round tiles, 1×1 quarter round tiles and 1×1 stadium tiles.
As with the previous texture, the idea is to be as random as possible in the placement of parts in order to get a realistic texture. I generally start by placing the bigger 2×2 elements first, then as many 1×2 elements as I can fit in the gaps between them before filling in the 1×1 elements last.