You will use a technique called dry brushing to make your trains look worn and old. Dry brushing is when you take your brush, spread out the bristles and paint with very little paint on your brush.
First apply a rust color to the springs and dampers and brakes on the trucks of the car. Remember to shake the paints well before using them.
Now add the color to the axel boxes and the top of the trucks. Then do all previous steps to the other side
Next you will add the color to the rivets on the body of the hopper car. Then do the same to the other side.
Now you add the rust to ladders and footholds on the hopper car.
Now take the black and use your brushes and cotton swabs to apply a mix of rust and black to make it look like it had carried many loads.
Just apply the finishing touches and there is the final product ready to run!