According to loads of psychology research, the most motivating goals are clearly defined and time-bound.
“While a fixation on results is certainly unhealthy, short-term goals can be useful developmental tools if they are balanced within a nurturing long-term philosophy.” — Josh Waitzkin
Your goals can either be focused on your behaviors (e.g., I’m going to write 500 words per day) or on the outcomes you’re seeking (e.g., I’m going to get published on Big Newspaper by June 1, 2016).
For most people, behaviorally-focused goals are the better and more motivating option. But when you crave the results so much that the work is irrelevant, your aim should be directed straight at the outcomes you want. However, results-focused goals are better when short-term and grounded in your long-term vision and philosophy. When your why is strong enough, the how will take care of itself.