Don't just break large goals into smaller tasks. For each sub-project, explicitly define the *new standard* of behavior, activity, or quality required. This shifts focus from merely completing tasks to executing them at a higher level necessary for success.
Once you achieve a new level of success (e.g., a revenue target), immediately treat that achievement as your new baseline or 'low.' This psychological shift forces you to maintain the urgency and work ethic that got you there, preventing stagnation.
To maintain high standards, your motivation must be specific and personal. Instead of abstract goals, define the 'why' in terms of tangible outcomes for specific people, like having energy for your kids or better serving a particular client whose name you write down.
Success comes not from defining desired outcomes (goals), but from raising the minimum level of performance and behavior (standards) you're willing to tolerate. You achieve what you tolerate, not what you desire, making your baseline standards the true driver of outcomes.