There’s something irresistible about the promise of bottomless mimosas on New Year’s Day. It sounds so — festive — even if I know that in real life, day drinking has a way of turning me into a depressed and maudlin sloth.

I did not want to start the new year as a depressed and maudlin sloth. However, I did want to start the new year writing. So at 9 am on Jan. 1, I found myself at Writers Blok for its Kickstart Your Year in Writing event: three hours of semi-structured writing time intercut...