Mark Hansen wrote:
Well, I do a thorough preflight and run up each time, regardless of the
maintenance schedule. I certainly cannot remove the cowl and inspect
the security of the spark plugs ;-\

Why not? The cowl on most types comes off with no tools. When doing
checkouts with new club members, I often pull the cowling and show
them what's underneath.

I certainly wouldn't launch into anything but day-vfr for the first
flight after major maintenance, and even then, I like to circle the
airport a couple of laps while climbing to a good altitude.