This is the best time of the year. So many wonderful things to see and do entrance me. Don't you love the holiday music in most stores? How about the swags and wreaths everywhere? And the sunny farewells from store clerks?
It's a great time to observe most people at their best. And why would that be important? Who cares if the usually grumpy cashier is has a quirk in his mouth that may suggest a small smile daring to escape? Why would you want to notice your bank teller is singing under her breath? Aren't you too busy for these little nuances to matter?
But matter they do to a writer. Building character traits that jive and work together are paramount. Your keen eye will help make your characters more believable when you use your observations. People are consistent for the most part. All personalities tend to follow a pattern that can help you categorize their traits. Yes, we all know that certain things make us individualistic, but there are still general traits that make up a personality type.
Observation is the best way to learn, and first-hand experience is key. With just a few extra moments, we can mentally catalog these changes in the behavior of the people we encounter on a regular basis. Later, take the time to write a few notes in a journal so you can refer back to them. This will improve your writing by giving continuity to the personalities you've chosen to work with.
It's great to read up on the subject too. There are excellent books on the subject, like Writer's Guide to Character Traits, by Dr. Linda Edelstein.
Keep your eyes open. You'll be surprised on what you pick up this wonderful, busy, sometimes crazy season.