Use your feelings:

• What would be a relief to get over with before the end of the year? 
• What is something don’t you want to be talking about planning to do next year? Instead, you want to say it’s done!

Use joy and regret:

• Joy: Yes! It would be great to get this done. 
• Regret: I would regret not getting this done now!

Use the calendar:

• Is there an event you want to be ready for?
• Is there an externally-imposed deadline that you need to meet?  

If you listed several answers, let these questions help you prioritize :

• Is there a sense of urgency, time-sensitive or otherwise?
• Did you promise to do it? 
• Are you expected to do it?
• Is it required by your management? 
• What is at stake if you don’t get it done? 

Tip: Replace (the end of the year) with the end of the week/month/quarter, your Birthday, Christmas, Ramadan, or trip. You get the picture.