ZBrush 4R7 - ZModeler & Array
Michael Angelo Hernandez has posted a timelapse video of how he uses ZModeler and Array in ZBrush 4R7.
How to Paint Rocks in Photoshop
Marc Brunet shares a free video tutorial on how to paint rocks in Photoshop.
Texturingxyz have posted a tutorial on how to use their displacement texturing in Nuke, Photoshop or Mari.