hopefully one or two brush is useful to someone
one brush pattern i got from here:
Skin Pattern 1.0 by Sed-rah-Stock on DeviantArt
the other i got from vector stock:
human-skin-texture-seamless-pattern-vector-8842293.jpg (1000×1080) (vectorstock.com)
adjust pattern scale to your desire of course. one brush i like to shift the pattern too so that it fills more on additional strokes
two others that may be worth trying:
made this texture too, should be seamless
