Eye mask, because wife likes to bathe the bedroom in blue light from iPad gaming when it's time to go to sleep.
Knee-pillow for spine alignment when sleeping on my side.
Sometimes ear plugs even though they don't do much, because the one, neighbour has a dog that yaps 24/7, the other neighbour lives behind the Gates of Mordor which open at ungodly hours and yet another neighbour has a muscle car that needs to be pre-heated at 03:00 for his nightly or early morning excursions into the hellscape that is life.