Stuff to leave at home:
- torch (unless you are flying at night and are prone to dropping things )
Checking all the instruments are illuminated is sodding difficult pre-flight if you will be flying through dusk.
I recently was very thankful of my torch after discovering that the compass and ASI illumination didn't work whilst in flight.
Also I fly, occasionally at night, a vintage aeroplane with no useful instrument lighting, and a single dome light behind my head. If that bulb goes, without a torch, I could well be in some discomfort.
And no light aeroplane I've yet to fly has a light that effectively illuminates anything strapped to my right knee.
I take a torch! It's hardly an expensive luxury. A couple of cheap cylumes bought of eBay are no bad thing as well. I have three nice little clip on LED ones which, including batteries, cost me £4.80 the lot from an eBay shop, and double for reading in bed without waking my wife up.
G