I've written an article on the Tudor Christmas at http://www.theanneboleynfiles.com/resources/tudor-life/tudor-christmas/, which you may find helpful. I would think that royal palaces would be decorated in the same way as normal people's homes, but on a grander scale. Tudor people would decorate their homes on Christmas Eve by bringing in evergreens like holly, ivy, mistletoe, yew, box and laurel.
