...someone mentioned dotting the plugs and sockets with nail varnish.
Me.
Don't need no fingernail polish if'n I'se wear'n my glasses & the light is good.
But I'm not always.
A red dot on the bit that I should still be able to see when it is in place is a great help. ( the bit with the funny arrow squiggle - which one can't always see easily )
Doesn't have to be nail varnish, but marker pen stuff wears off, and if you use a paint pot, brush, turpentine, rag etc. which are doubtless in the garage, and it's raining, then clean the brush - Oh ! you know, easier to buy a bottle of red nail varnish from the $2. shop, this comes with handy brush attached to the top and you don't have to clean it afterwards.
Apply it to one of the many keys on my key ring too, you know, the one you need all the time and can never sort out fast enough. (doesn't work in the dark tho' - a code of filed notches sorts that out.