This video will help when I have to add details to the wood of my siege cart model.
ArtStation - ZBrush Wood Work, Anna Smirnoff
Wood board sculpt, Blake Maier on ArtStation at https://www.artstation.com/artwork/wood-board-sculpt
Woddendbox, Choi yong on ArtStation at https://www.artstation.com/artwork/woddendbox
[WIP] Tower scene [UDK] - Polycount Forum