Years ago I needed to catch a “red eye” flight to a trade show and I asked a world-traveling friend for some tips that worked for him. As far as sleep goes he mentioned two essentials that he kept with him as he traveled, namely a sleep mask and ear plugs. Although I appreciate the darkened effect over my eyes I tend not to use ear plugs or head phones as a rule because I like to be aware of my environment for safety reasons.
Later, on a long train trip I learned to use a hat over my face as a “zone” to slightly muffle sound, darken my closed eyes, and let others know that I was “off limits” for interaction. In lieu of wearing a hat I discovered a new darkening device… my wallet! It’s something that I always carry with me that is compact, can unfold, and has a ridge line in the middle that allows it to cover the bridge of my nose and follow the contour over my eyes and does a remarkable job of darkening.
This works well in a safe/secure environment like inside your car or private room but perhaps a folding note pad or pocket calendar would be safer to use in a Public place such as a terminal or park bench. In any event it’s great to have a portable device that helps you get the quick recharge that you might need to carry on your day, enabling you to have a brighter outlook with better focus for your ongoing journey or task.