Finishing important tasks creates a feeling of accomplishment, giving you more motivation to plough through the secondary projects and lesser requirements.
Prioritize tasks by organising its urgency and scope. Lay it out on a paper or for a more convenient way, log it in Daily Notes.
On Daily Notes, you can prioritize tasks, from low, medium and high. You can also easily what needs to be finished for the day, when is its due date and those that are pending. You can easily move a tasks around, depending on its urgency and your schedule.