I don’t know if it would work for anyone else, but chewing gum keeps me occupied when inattentive and watching something, or any activity where I’d be snacking without noticing.

Other comments mention many other options. But sometimes, none of the tricks work, and that’s usually due to a stressed+bored combo.

To me, the most useful trick was to set my wristwatch 5 mins ahead of the local time. These days, I only use my phone as a watch but the same principle applies. Catching up bus times was my biggest problem, especially when I needed to use more than one bus line.

You’d think it wouldn’t work since I know I technically have 5 more minutes but reading the time as 07:00 instead of 06:55 was pretty effective for me.