This may sound ridiculously simple but here it is: Get sleep.
Particularly coming up to Christmas, we are stressed, or excited, and may be socialising more. And often, sleep suffers. And remember – alcohol interferes with sleep – it does NOT enhance it, and it IS a depressant. (Those of you who have woken up in the horrors and had a ‘down’ day after a ‘great’ night will know this).
Mind your mood.