An easy way to enhance the look of any diesel locomotive is to blacken the grills and vents to provide more depth.  You can use a black wash to bring out the grill or vent details.  Weathering powders are extremely effective bringing out locomotive vent and grill details.

Stonebridge Models Greenhouse Build by Modelersguild.com

It's funny - Sometimes in this gig, I come across a project that just amazes me. This Greenhouse [ ... ]

Hopper Weathering Clinic III
By Bill Mock
January 2010

OK, I gave the inside of these hoppers a wash of Engine Black below the coal line. They [ ... ]

This is a test of some photos I took with my iPad2. It's all z-scale stuff - code 40 ME unweathered rail with z- and n-scale PCB ties from handlaidtrack.com. [ ... ]