PBR texturing
Check the short tutorial.
Also, with PBR the diffuse shouldn’t have shading in it, try to make it as flat as you can (no shadows no specular), most of the details will be expressed through the specular and the normal.
hopefully this will help new modders having problems with specular maps.
The sample texture comes from Gratuitous Retexture – Chessboard by kingADZ12