One of my players suggested this a while back. These are little things we do at the table to keep track of things more easily.
Flying Dice - Characters who are flying have their minis placed on a large 6-sided die, with the number representing the height. If you go up higher than 6 yards, we add more dice to the stack.
Since generally people use spells like Levitation in my game, it's rare for high flyers to be zipping around. Especially so in dungeons. So D6s under the mini work just fine!
Great Haste D10s - We count the 10 seconds of the Great Haste spell down by using a d10 from ye olde dice collection. At the end of each turn of the spell, the dice is turned to the next number down. It makes it easy to track the length of the spell.
We've done a few others over the years, but those two have stuck forever.
I am thinking of digging out my poker chip collection - bought precisely to use for status - so we can track people who are stunned or used AOA (in a really big fight, those can be hard to remember!) But I don't know if they'll stick like the flying dice or Great Haste tracking d10.