It’s come to this.
Drove 4/5 of the way to Toronto (from London) to see a concert only to realize I forgot my concert ticket at home. So hopefully this checklist will help in the future.

The idea is to run through this list the night before.
This list is for me. It caters to my shooting style, subject matter and equipment.

01. Concert ticket! (recently forgot it, that’s why it’s on top)
02. Ear plugs.
03. Snack / medication pouch topped up.
04. Camera batteries recharged after each and every shoot – no exceptions.
05. Flash(es) batteries recharged after each and every shoot – no exceptions.
06. Set ISO to 200.
07. Wipe clean all lens glass.
08. Make sure all lenses function properly.
09. Set aperture to wide open on all lenses.
10. Set shutter speed to 1/125
11. Set mode dial to Aperture Priority.
12. Check that the camera body and any/all lenses are set to autofocus.
13. Set white balance to AUTO.
14. Check setting of exposure compensation (set to “0”).
15. Reset the focus point to the center.
16. Set motor drive to single shot.
17. Empty all memory cards.
18. Pack lens pouches.
19. Do quick visual examination of the camera, lenses and camera bag to look for damage defects.
20. Reset additional gear like tripods, light stands, etc.

Thanks for info from Scott Bourne and photographr.info.