Right now is a GREAT time to find Christmas things on the Disney Website Store that you can use for your next trip in December...they have some things up to 70% off and if you purchase $89 worth of merchandise, shipping is $5.00. They have Disney Christmas stockings for $5.99 that were regularly $24.50, lots of t-shirts, sweatshirts, some ornaments, stuffed animals (there was a really cute Christmas Dumbo that was super cheap) etc.
Here is a link:
http://www.disneystore.com/sale/holiday/holiday-decor/holiday-ornaments/c/309605/
I loved the small Christmas tree that we had in our room. If you can find a way to take one or mail one in advance to your hotel/condo with a wreath...it is fun to decorate your door and room to make it look Christmasy and festive. You can get fake christmas trees half off right now at stores. If you can find one for around $10-20 and mail it to your hotel...you might not care about leaving it behind. And if you do...maybe a mousekeeper can enjoy it in their home, so make sure you leave it behind with a note. If stores are already sold out...get one at Michaels with a 50% off coupon when it gets closer to Christmas or Hobby Lobby when they are one of their weekly sale items.
I love the idea of blankets. In the "Mickey Grand Welcome" they embroider a blanket with your family name, WDW and date (there is a picture of it on the website link in the first post). It isn't very expensive to embroider names and dates to things so be on the look out for blankets that you can do this to, or if you find a Disney theme fleece...you can make a no sew fleece blanket. You can google online for directions. These are super easy to make! Here is one website with instructions:
http://www.exploringwomanhood.com/homelife/ideas/pom-jan03.htm
Take some time to look through the current pages on the Creative DISigns Forum and save the links to the Christmas threads so that you can find them when you need Christmas images, t-shirts, welcome signs, etc.
Also, look at Dollar Stores and see what Disney things they may have in the after Christmas sales to put in Disney stockings. Or even the regular sale price as they tend to have more Disney things around Christmas (the Dollar Tree always has lots of Disney things). Some things to look for that you can add to their boxes/bags/stockings are disney puzzles, coloring books, crayons, frisbees, pencils, pens, magnets...the list is long especially around Christmas. They even had great Disney stuffed animals. You might also look in Christmas sale items at Wal-mart, Target, etc. to see if you can find Disney stockings on sale...go today!!!
Hopefully that will get you started.