In this post I'll show how I fix the track with nails, because what everybody does is use a small hammer, but this doesn't work well (at least for me...) because it's difficult to keep the track in the exact place while the nail is going deeper, and many times the hammer hits my fingers instead.:@
Firs of all I prepared a gauge with a small piece of wood making some slots to fit the tracks at the desired space for the hidden yard:
After the track is in place I insert the nail in the place to fix and I use an old and small file which is 8 millimeters wide, so it fits between the rails:
You only have to make some pressure on it and the nail will enter smoothly because it doesn't slip from the file .
Many people only uses nails at the beginning and end of a track section and glues it, or directly only glues the track. But for the hidden yard I prefer to use only nails because it's easier to dismount if someday it's necessary.
In this way the track will be placed exactly where you want. I hope it be useful!!!