Women's weakly 1969
Actually I learned that one from Railway Modeller back in the early 1980s when I built my own model layout as a kid
It's a quick way to put ballast under the track, you mark out where the track is to go, spread PVA glue on the base board, pin down the track, then just pour the ballast along the length.
Wait for the glue to set and use the J-Cloth trick to vacuum up any that hasn't stuck