Editor's note: Inc. asked eight entrepreneurs at the top of their game to track for one day (Tuesday, November 29, 2016) how they spent every single hour. Productivity expert and author Laura Vanderkam then weighed in on what they're doing right, what they may be doing wrong, and how you can apply their productivity skills to your life.

When Barbara Corcoran, 68, sold off her real estate firm, the Corcoran Group, in 2001,
she reached a milestone that leads many entrepreneurs to call it quits. Seven years later, producers for Shark Tank came knocking. Today, she's called on to appear at more events than ever before, while raising the family she and her husband started after she'd spent years hunkered down in the cutthroat real estate world.

Make the most of those 24.

I have a young family to care for, and I wrestle with apportioning my time and focus
between my obligations at home and the demands of my business. Like every entrepreneur, I'm pulled in way too many directions, and I often feel like a puppet on somebody else's string, jockeying my time between family obligations, helping the entrepreneurs I've invested in, filming Shark Tank, and flying to motivational speeches in multiple cities. Too much on your plate gets in the way of building the business you dreamed of having when you first started out. Lucky for all of us, time is reliably fair and doles out 24 hours a day to everyone, but it's how you make the most of it that really counts.

All hail the paper to-do list.

I organize my to-do list to accomplish the growth I care so much about. It helps me avoid feeling like a jack­rabbit jumping from one task to another and not completing the important things first. I make my to-do list at night, transferring items I couldn't get done that day. I also email items to my assistant as I think of them when I'm traveling or outside the office. I rate the items in order of importance: A, B, or C. The A's are where the gold is. These are the things that will move my business ahead and make me money. I find there are really only three to five A items on any given day, and I do those first. I always schedule and tackle A tasks in the morning, as it's my most productive time. My to-do list is in charge of my life, so I give it proper respect. I've tried different online to-do lists, but the Delete button never gives me the satisfaction that I get from crossing off an item on paper.

Laura says: Pick three.

We often think we'll get through 40 things a day, but guess what? We won't! Better to come up with three A tasks for the day, and make sure you get through them. Doing three important things per day is 15 per workweek. That's 750 per year. That's a lot of important stuff.

Divide and conquer.

Here's what I do: I divide my world into two parts--my business and my family--and I keep them totally separate. When I'm at work, my husband and kids and friends don't call. Everyone has my assistant's phone number for any emergency, and Gail knows how to find me. When I'm at the office, work is what I'm there to achieve. I never think of my kids. When I get home at night, I focus 100 percent on my family. There's dinner, the usual homework, bedtime routines, and the mini crises that come with all parenting, but at night I don't check emails or answer the phone. I plug my phone into the charger at the front door, and the next morning, I grab it as I walk out the door. I realized a while back that the constant flow of emailing and texting was my personal enemy and declared war. It was stealing the precious time I had with my delicious kids. Not anymore. I'm smarter, and I divide my life into two separate parts.

Use your history to plan your future.

I like to organize my week so similar tasks fall on the same day. It makes me more productive. Past behavior is the best predictor of future behavior, so I sit down twice a year with last year's calendar in hand. I find repetitive work patterns to organize my tasks more effectively. For example, last year, most of my speeches fell on either a Tuesday or Wednesday. So I plan my long-term meetings to avoid Tuesdays and Wednesdays. Most media interviews last year were on a Wednesday or Thursday, so I have time blocks in my calendar on Thursdays to anticipate those calls. I also plan my calls to clients, consultants, and producers in the same time block when I'm at my desk anyway, as it's more efficient. On Mondays, I focus on all my long-term A projects, delegating portions of them and following up before the week kicks into high gear. It also sets the tone for the week.

Laura says: Past is prologue.

We treat past calendars as easy things to delete, but they can hold clues to help make us more productive. If a particular client always calls you with big requests on Friday, reach out earlier in the day on Friday, or even on Thursday, to get ahead of the problem.

FROM THE APRIL 2017 ISSUE OF INC. MAGAZINE