Because our reservoirs of will and discipline are astonishingly small, in order to make lasting changes, we need to develop rituals, highly specific behaviors that we do repeatedly, at the same time, until they become automatic in our lives. Brushing our teeth, for example, is a ritual that hopefully all of us share.

One of the most important rituals that we encourage our clients to adopt is doing the most important thing first in the morning. The idea is to ensure that you do the most challenging and important work every day when your energy is higher and you have fewer distractions. This means you're starting your day with your own agenda instead of letting email (read: others) dictate what your day will look like.

You can use this worksheet to help you set up your ritual and try it out for a week. The first step is to think of the most important tasks that you need to accomplish this week, and add them to the sheet. Designate exactly how long you're going to work on each task, with a clear start and stop time. And stick to it. You may have to work around meetings that you have no choice but to attend at the beginning of your days. The important thing is that you should add these times into your calendar, and treat them as sacredly as you do a meeting.

When you sit down to do your "most important thing," focus intensely for up to 90 minutes, without interruptions, and then get up from your desk and take a break to truly renew and recharge.

Then, you can return to your worksheet and mark how much time the task actually took you. If it lasts through more than one 90-minute session, then simply wait until the task is complete before marking it down on your sheet. This will help you not only to make time for your most important, long-term challenges, but also to get a better sense of how long it actually takes to finish a task -- something we often grossly overestimate.