As a member of a family who has no history at all in shoes...making or wearing... [bustagut] I really don't have a clue but...
I wondered if using the Texturizer filter might help. If you do a complete install of Photoshop, including all the Presets, there are a zillion possible files which you can load into the Texturizer filter. The preset texture files end up in... Applications:Adobe Photoshop CS

resets:Textures and another file with the same path, Textures for Lighting Effects. In the Texturizer window you click on the triangle I've circled in green, use Load Texture and navigate to one of those two folders. In TfLE folder there are a couple of leather textures but I didn't think they looked quite right. On a whim I loaded Footsteps in the Textures file and thought it looked pretty good. A few scratches and it might work. If you look at the texture files themselves, you can create one which might work better.