Every semi-sophisticated man should have a flashlight. Yeah, I know your phone has a light. Good for you. Try holding your phone in your mouth to light things up while you use both hands. Not so easy, huh? A flashlight doesn't take up much space in the pocket, but will come in handy more often than you might realize. If you are like me, your eyes get a little worse every day, and eventually you will end up using the flashlight just to find your shoes.
This is my favorite flashlight. The Nitecore Sens AA. It works on a single AA battery, which is important to me because I don't want to have to look for special batteries when the time comes. It's a twist-activated "on" switch, so it doesn't accidentally turn on in your pocket.
Here's the best part... If you turn the flashlight on while it's pointing down, it assumes you're reading a map, and provides a light dim enough to not wreck your eyes. If you turn the light on while it points out at 45 degrees, you get a medium light that will show you if you are about to step on a LEGO block. If you point the flashlight straight out and turn it on, as if to light up something far away, the beam is extra bright. It's magnificent in its ease of use.
You could try dressing it up with some glitter and ribbons, or paint some cute dots on it with pink nail polish! Mine's been finely detailed through countless hours of artisinal rubbing with a finely-curated set of metallic instruments, which also serve to unlock my house and truck.