I was going to buy some real HO track but found some very cheap plastic tracks on Amazon and I got some rail bed from a Train Terrain company. The whole thing was less then $30 and I probably have another 8-12' of track materials still left but what I needed was a something to cross a 6' terrain table.
It was a bit more work than I thought it might be. The track was a little too wide for the bed but I plan to improve that when it is set up with clumping foliage. I used PVA to glue the track to the bed which is some sort of foam and then sprinkled the ballast on the wet bed, it was not really the best method but with some repairs I moved on. Once dry, I airbrushed the whole thing with black, followed by a green brown followed by a light brown. I then drybrushed the whole thing with a light sand colour. I then washed the rails with black followed by a drybrush of a dark metal. I then used a brown ink from Scale Colour to paint the wood, which really worked quite well. I finished off the tracks with a rust wash.