Ballasting
For ballast I used Woodland Scenics Fine Gray straight. I used the classic, well known method for ballasting:
Lay the ballast dry;
Soak the ballast with straight denaturated alcohol (isopropyl works as well);
Soak the ballast with diluted white glue (50% white glue, 40% water, 10% denaturated alcohol);
I found out that using hot water really helps in diluting the white glue. I use a syringe to soak the ballast with liquid, slightly pressing the needle against the rail side to avoid messing up the ballast.
Weathering
I think one of the most important elements of scenery is track. Properly ballasted track is not enough for a convincing scene. Track needs to be weathered. I airbrushed all the tracks with Floquil Railroad Tie Brown before ballasting. After ballasting, I weathered the ties and ballast between the rail using a mix of 50-50 black powdered pigments and plaster of Paris, using a wide enough brush to spread the mix along the main line.
Click for a link to a video howto I did to show
track ballasting.
These techniques are also demonstrated in video by Joe Fugate and are downloadable for few bucks at
Model Trains Video website.
Please note that I'm not affiliated with Model Trains Video in any way, I just have the whole DVD catalog and found Joe's tips and trick very helpful.