Attend as MANY conferences as possible - I cannot overstate the importance of this. Tattoo the new company's logo onto your chest whilst reverse engineering Microsoft PowerPoint down to machine code. Ask the firm you are joining if you can come and "hang out" for a couple of months - and try to get a good desk with a nice view of a pretty lady (or gentleman, the world is diverse now). Finally get ANOTHER tattoo of the company's logo on your lower back, re-engineer PowerPoint as a German Shepherd dog called Alan, get a mug saying "Worlds Greatest Boss" and a selection of dubiously festive ties.....
....alternatively, realize what a lucky son-of-a-gun you are that you can enjoy the festive period work-free, go get drunk, spend time with your family, travel, write a book, get drunk again...