December can be closed quite efficiently if you do not get distracted by all the fun things you could do. You can finish a lot while everyone is unwinding and partying. If you made your to-do list for this month, you know where to put your focus. If you manage to check off everything, you will start with a clean sheet in the next year. You should aim for that, because why would you want to carry dead weight if you can cut it loose in this month? Focus, then get to work. Sleep when the work is done.