I wanted to get a better sense of time, so I configured my phone to vibrate every half-hour in a short pattern of two quick bursts. That way, I can feel time passing, and I can distinguish these vibrations from message alerts. I used the following Tasker script:
Profile: Buzz time (13)
Time: From 08:00 every 30m Till 22:00
Enter: Anon (14)
A1: Vibrate Pattern [ Pattern:0,100,100,100 ]
After the quick buzz, I usually glance at the clock to confirm the time. It's a handy way to remember that time is passing and that I should make the most of it. It's not a big distraction. I can still stay in flow when I'm coding or writing. If I find myself wandering, I can bring myself back.
I don't remember whose blog post started me down this path of making time a sense, but that was a good idea. (If you recognize yourself, please comment!)