Mxsmanic wrote:
What things do you consider it essential to always have on board for
every flight? Not just things required by law, but things that you
personally believe in having on the aircraft before you leave the
ground.

For flight: Flashlights. Pens and mechanical pencils. Batteries.
More flashlights :-)

For emergency landings: These days, a cell phone. Matches. Water.
Leatherman tool. Blanket if it's cold.

Kev