Inspired by a discussion over in the Discord…
Beyond what game texts require (dice, pencils, etc.) what are some the tools you use when running a game?
@RumpleFrumpkins mentioned clipboards, and I second that recommendation. I keep GM and player reference sheets in mine for easy access when I need to double check a rule or procedure.
I like to have plenty of index cards accessible, a lot of gaming ephemera gets generated on them. We sometimes use paperclips to track things like HP instead of doing math. I have a bunch of little LED votive candles that the player carrying a torch keeps in front of them as a reminder that they have a lightsource in their hand.
The torch tracker is a cool idea. Might be fun to have a light with stepped power levels, and click it down to represent the gradual consumption of the torch.
There’s a little remove control that I use to make them flicker sometimes 
I made a little album of my “go bag” for playing RPGs (one shots or regular sessions).
I have:
The best tool I’ve used when playing in person was just a giant piece of whiteboard material that covered the whole table.
If you get something un-framed it’s very cheap, and you can even score a section of it with a knife to make a grid if you want (although this takes a lot of careful measuring).
It opens up a lot of opportunities. Players can track their HP without writing directly on the character sheet or diagram out a plan in full view of everybody at the table. As the GM I can write out bits of information as I give it to the players, so they won’t even forget NPC names every five seconds.
As the GM, I generally just sketch out a rough battlemap rather than use a grid, which serves more as a reminder of terrain features than a strictly scaled battlefield. Using a whiteboard means that this can be done more or less on the fly and you can work with the players when sketching out the area. You can even abandon miniatures entirely and just draw the locations of PCs and enemies on the map.
This is really really cool! What bag is that? I’ve been looking for a good one.
It is this one
I’ve had it for like, 5 years.
Oddly I find most of my tools are meeting management skills.
The stuff you learn about being a good presenter, taking notes, delegating task, and running a meeting are the most valuable tools. Especially for online play where Zoom fatigue is real.
For material supplies, my maps scanned, my Gdoc of room keys, a good die roller, some scratch paper and a pen. Maybe real dice if I feel frisky. I keep a few PDFs open for reference - game rules etc.
If I’m running someone else’s stuff I print out the map and make notes on it while reading the adventure so I don’t miss important bits in game.