Okey here´s a quick shot: In a project I did a mix of the following things for a character displayed in a cutscene: I created a mask in photoshop that seperated the parts of the texture that I want to work on specificly. I multiplied it with a "strengthened" normal (normal masked through a RG Mask and a B Mask. The RG Mask was then multiplied by ... lets say 2 for testing and then I merged the RG and B together with an append) so I would get stronger/deeper detail on the part of the texture.
Second and most intersting part is to go into photoshop and apply some textures on your base texture. This would also involve doing this with the normal maps (I use NVIDIA tools for photoshop...maybe not the best though.) were I converted the additional textures to normals and set their layer to "overlay" wich will blend it with the base normal map.
It takes a bit of back and forth between PS and UDK though. This is less technical and more artistic. Also lighting and general material setup play a huge role in this. Sometimes I´d use a fresnel node to enhance some details of the cloth. Also it is important how shiney your cloth will be...will it be more like satin or more like rough wool, etc. etc.