Before I started my own company, I worked as a software developer for a New York media company. I had a colleague—let’s call him Neil—who was a brilliant designer. But he was also a perfectionist.

How you approach or create your to-do list can make a big difference. Experts weigh in on how to write — and tackle — a to-do list to make it best work for you. As we head into the new year, maybe you ...