You need two things to enjoy your work: clear goals and immediate feedback. A pro golfer, for example, knows after each stroke whether it was a good or bad shot. The goal is clear: to get the ball in the hole. And the feedback is immediate: he is closer to or farther from the hole.
Other activities are more ambiguous. Designing a brand, for example. The goal in profit terms is clear: design a brand that will sell the most units. How this translates into the design is less clear, however. So that setting intermediate goals—for deciding on the color scheme, drawing the logo, and launching campaigns—may be more nebulous.
And feedback is not immediate. Until units hit the market there is no data on how the brand is performing. So for these ambiguous tasks like designing a brand it becomes important to set clear intermediate goals that provide feedback. And these intermediate goals must be in-line with the ultimate goal.
Source: Mihaly Csikszentmihalyi, Flow, pgs. 55-58.