Drill pilot holes first to keep the boards from splitting.
In more dense soils, a pilot hole is drilled into the earth.
The saw has a central drill bit, and fit this into the pilot hole already drilled.
Drill pilot holes along the inside edge of the casing.
When the head and side casings are in place, drive a 4d nail through the top pilot hole.
You will have to drill a pilot hole for the bolt.
However, with either fastener, drill a pilot hole into both pieces first.
Countersunk: First you drill a pilot hole into the wood.
The job will be easier, however, if you drill pilot holes first.