You chew on the back of a pen, or you meticulously flip a paper clip with your fingers.
Or, if you're a school-aged child today, you spin the fidget.
While it's not uncommon for people to ease their nerves with a repetitive sensory motion, some say the technique can make an even bigger difference for children with neurodevelopmental disorders.
Now, a device specifically developed for students with autism has shot into the mainstream. The spinner fidget — a small device that can be held with two fingers while the propeller-like portions twirl at rapid speed — is showing up en massein classrooms.
But whether that's a good thing or not is up for debate.
Terri Duncan, the executive director for Children's Autism Services of Edmonton, said she thinks spinner fidget could be a useful classroom tool.
"Fidgets in general are useful, not just for kids with autism, but for lots of kids and in fact for lots of adults," Duncan told CBC's Edmonton AM Tuesday. "Lots of adults will pick up a paper clip or a pen, to fidget with.
"Those things are calming. We have to remember these are calming tools that kids can use to help them learn."
Fidgets can be anything that keep the hands busy and moving, Duncan said. They're used to help children calm down and help them focus on their work.
In the United States, teachers faced with rooms full of students obsessively twirling the devices have banned fidget spinners. But Duncan said there is a need for a broader teaching moment.
"I believe that all kids need to learn how to self-regulate and to self-regulate, you need to know what helps your body calm and what helps you think and focus," she said.
"All kids learning how to self-regulate is great. Do they all need to self-regulate with that particular fidget toy? Probably not. But it's a good opportunity to teach kids there are lots of things that you can do to help your body stay calm, alert and ready to learn."
Children's Autism Services of Edmonton runs a social enterprise called Therapyware that sells equipment, materials and books for children, including a number of fidget toys. They can range from a few dollars to $30.
Duncan said it's a small price to pay to help kids use the tool to learn the important skill of self-regulation.
"I think it's a great opportunity to teach all kids how to use that tool — the same way they'd use a pen, or a pencil, or a ball chair," Duncan said.
"So rather than take these away ... these are tools they need to learn how to use appropriately."