My end-of-year routine:

Stay somewhere fun with best friend (aka wife) for a couple days. Eat and drink well. Go for walks and run. 

Reflect on the year by creating a best of a photo album, thinking about things and people I like/dislike and want more/less of in my life, reviewing goals versus actuals, watching past years' midnight videos, and comparing notes.

Set goals for the following year by mapping out 10yr-5yr-1yr, creating a yearly schedule for travel + important dates, and recording a semi-drunk video after midnight 🍾

It's not perfect, and I know I could do a lot more, but it's fun and works for me.