Yesterday I started ballasting the track. So far I have only done a short stretch. I started with some sand on the sub-roadbed, below the actual roadbed. Here is a picture, with the sand still wet from the white glue and water mix.
Next I ballasted the siding with the minitec "Standard-Schlotter Phonolith N" ballast, which arrived from Germany a few days ago. On the mainline track I only put this ballast on the slopes of the roadbed. As you can see below there is still now ballast between the mainline ties.
Instead I used Woodland Scenics Gray Blend for the mainline. The idea was that this lighter ballast should represent newer ballast, while the siding had to make do with old ballast spread at some earlier stage.
The effect turned out to be very subtle. I might try to use a little more of the lighter ballast for the rest of the mainline. Anyway, here is a last picure from a slightly lower vantage point.