you dont want to list it auction style the weekend before christmas, or a few days before christmas because
1) people would rather get it now, so buy it now is a good choice.
2) if you still do an auction style listing, chances are your items will end relatively less than it did the previous week. if say you sold a guitar hero metallica for $36 last week, youll probably only going to get $20-$25 at the most this week.
you can also either mention that you can ship it so that the package will make it there on christmas or you can say that it wont. saying that youre assuring them of delivery before date is attractive to buyers. you can also leave that out if you want.
but if you have a great deal of stock you need to get rid of, then just wait until the 26th to list. again BIN would probably be your best option as people are probably done shopping and your listing will end less if you do auction style. good luck.