Mike Cougill over at OST Publications is an inspiration when it comes to modelling track. His work is in O scale sure, his techniques however can be used in any scale to spruce up, or in this case make a mess of, otherwise perfectly good track.
His recent post about modelling oil soaked track is a point in case. Simple, presented in a straightforward style and always willing to experiment Mike’s technique provides a great result.
Mike’s site is full of great articles and ideas. Very well worth the time taken to visit.