You might be tempted to start your day with some easier tasks. After all, who doesn't love to show a little progress? That said, you might be wired to enjoy things more if they become easier over time. If you dedicate the first part of your day to tackling a tough task, and relegate easier work for later, you might enjoy the process more and suffer less. Otherwise, you may find that the tough tasks get kicked down the road, deferred, and prioritized lower in favor of smaller wins. If you're the type of person who has peak energy shortly after you start work, block off that time in your calendar and commit to doing the tough tasks first.