...please don't drink and drive (and be extra cautious when driving because not everyone heeds such advice).
...ratchet back the drama (the holidays can be difficult for people so be more giving/patient/ understanding if people aren't at their best over the holiday).
...be prepared if you will be traveling in inclement weather (be sure to have emergency gear with you as well as chains/emergency car stuff as well).
...did you know that heart attacks peak each year on Christmas Eve? I didn't either until I saw this article. As usual, be prepared to notice if someone is having a health issue and also be prepared to render assistance if necessary.
...lock up (don't just hide) guns, drugs, poisons, etc. so kids and animals and your third cousin's tweaker kid won't find them.
...be grateful for the things you do have--family, friends, health, a job, a home, etc.
...if you are alone for the holiday, there will be a bajillion people on reddit so you needn't feel alone; hop online and converse on the topics of your choice to your heart's content.
And some emergency resources: