In the manufacture of furniture with the use of plug-in round thorns is very important equally to mark the holes for them on both abutting parts.
A simple jig can turn… pushpin. They are easy to attach with glue or small nails on the wooden rail so that they were at a certain distance from each other and edges upwards. Pinhole, this pattern marks on both parts, you can be sure that the holes for the spikes will line up perfectly.