Here comes the fun part, trying to find out what your target wants for Christmas! You could ask family members, friends, maybe search their blog (if they have one) for ideas. We always find it easy if each member has a Wish List which lists what they want and allows you to buy an item from it and ship it to them secretly all in one go! You can read more about Wish Lists in the Wish List page.
Of course you can always buy a present old school and give it to them yourself!